. one of the most direct condemnations yet of the increasing death toll in gaza from a u.s. official. the secretary of state saying today, far too many palestinians have been killed. while israel announces another evacuation corridor to get civilians out. we'll take you live near the israel/gaza border in moments. plus, stark warnings from american diplomats in the middle east. a diplomatic cable to the white house highlighting the growing anger from the arab world for america's strong support of israel's military offensive and the humanitarian crisis it is creating in gaza. and federal law enforcement officials investigating after more than a dozen suspicious letters were sent to election offices across the u.s. at least one is believed to contain fentanyl. we're following these major developing stories and many more coming in to cnn news central. as night falls on gaza, we're seeing more fiery explosions rock the enclave. moments ago, cnn crews witnessed a heavy barrage there. israeli forces intensifying their attacks against hamas with many civilians caught in the cross fire. we have new footage to share with you, but we must warn you, it is graphic. the new video obtained by cnn shows a young girl pulled from the rubble at a collapsed school in gaza. it's unclear what caused the blast, but sadly, it is just one of several incidents involving civilians today. there are reports of israeli air strikes damaging several hospitals as well. the idf maintains it is exclusively targeting areas with ties to hamas, and any civilian losses are unintended. ahead of the elnassar hospital say israeli tanks are surrounding his facilities, cutting off patients and doctors from water and critical supplies. a short time ago, we learned president biden spoke with the leader of oman as unrest builds across the middle east between the u.s. and iranian proxies in the region. there are also growing international demands to further address the dire humanitarian crisis that is currently unfolding in gaza. speaking today after meetings in india, the secretary of state antony blinken gave one of his most direct condemnations yet of the mounting death toll. listen. >> much more needs to be done. to protect civilians and to make sure that humanitarian assistance reaches them. far too many palestinians have been killed. far too many have suffered these past weeks. >> meantime, thousands more of gaza's citizens escaped south today as israeli forces opened a six-hour evacuation corridor with a promise of more pauses in the future. let's take you now live to the region with nic robertson, live for us at this hour. moments ago, you saw the sky light up. what is it looking like now? >> reporter: yeah, the sky is dark, but i can just hear this rolling thunder of explosions and detonations coming from that same area in the northern part of gaza strip. we think it's the refugee camp. we can't know for sure. what we were witnessing a short time ago were those illumination flares, the ground spoke, and the air strikes coming in on a confined location there within that camp area. and it seems to indication from what we have seen before, it would mean that probably idf ground troops were going into a certain area, having specific information about hamas targets and operatives there. i think what's striking about this incident right now, two weeks into the ground offensive, that they have been operating in this particular area for two weeks. that they are still, it appears, finding elements of hamas that are still there, still fighting on the ground because that's why you would need the flares and the smoke screen for the troops, the idf troops to move in behind, the strikes called in, and these ongoing detonations seem to indicate the fight there is far from over. idf forces are south of here, south of the refugee camp inside gaza city. the humanitarian corridor, tens of thousands of people have managed to evacuate from the north to the south today. but so many questions being raised now, particularly about the health care system, the international dmcommittee for t red cross saying the health care in gaza has reached a point of no return. the hamas-led ministry of health says 193 health care workers killed, more than 60 ambulances have been damaged by strikes. they say 21 of 35 hospitals are out of action. 53 of 72 health care clinics are now out of action. so the picture that emerges is that while the idf is continuing to fight hamas, is helping some civilians as well avoid the worst of the battlefield traumas. people, as you saw that child being pulled from the rubble from a school that appeared to have been hit or there was an explosion there a short time ago today, civilians are still getting caught up in this. 11,000, more than 11,000 have been killed. and i think this is the reason that we're seeing this growing international diplomatic pressure that the united states is feeling and secretary blinken was expressing and is arriving on the doorstep of netanyahu. >> nic robertson, thank you for keeping us updated. brianna. at the same time, cnn is learning american diplomats in the middle east are warning the biden administration of growing fury in the arab world against the u.s. for its strong support of israel's deadly military campaign in gaza. cnn's natasha bertrand is here with more on this. natasha, cnn has obtained a diplomatic cable that shows this. tell us what it says. >> reporter: this was a cable written by the second highest official of the u.s. embassy in o oman. the president spoke to the sultan of oman today. what this official was warning the white house, the fbi, the cia in this cable is with all of these images coming out that we have been seeing in gaza of the palestinian civilians being buried under the rubble, of all of the thousands and thousands of civilians being killed, it is sparking a real uproar and backlash in the arab world against the united states was the u.s. it appears to the arab world is supporting israel's campaign really unconditionally, and the sentiment that is being expressed to u.s. officials in the region is that they are, quote, losing the arab public for a generation and that u.s. support for israel is being seen in the arab world as, quote, material and moral culpability in what they consider to be possible war crimes. so this backlash obviously it poses a serious risk, of course, to americans who are in the region. we have already seen iran and its proxies exploit the tensions and anger, launching attacks on u.s. service members in the region. it has real consequences. the u.s. is trying to really toe this line between of course supporting israel and its war against hamas and retaliating for the brutal terrorist attack on october 7th and also disagreeing with how israel is carrying out this operation. from the very beginning, they have been urging israel to be more precise and limited in its campaign, something israel does not appear to have heeded in the last several weeks. the secretary of state is resisting calls from these arab allies for a cease-fire, and at this point, the u.s. is backing humanitarian pauses, but for the arab allies. it's not enough. >> is it unusual to get a look at one of these diplomatic cables? >> reporter: it is. we have seen more leaking over the last several weeks because of this discontent, because these officials want the world to know there is all of this anger. >> and the biden administration is being counseled on it. natasha, thank you for that. let's dig deeper now with retired u.s. army major mike lyons. thanks so much for being with us. first, i want to replay that video that was captured moments ago. the bombardment in gaza. to the untrained eye, it looks like a series of explosions. obviously, you can give us perspective on what's happening. walk us through what we're seeing. >> sure, so israel would own the night if it was a conventional fight with their night observation devices. in the urban fight, they can't use that technology. what they have to use is illuminating flares from artillery or mortar rounds. thennia can see what they're doing is calling in accurate artillery fire. that's the other side to this coin, making sure they're hitting targets that are from their perspective military targets. it allows them to turn the lights on when they want, hit a target, and then the illumination goes out, goes dark for a while, then they decide to turn the lights back on. a classic example of how you have to fight in an urban warfare setting. >> i wanted to ask you about that diplomatic cable that natasha was just reporting on. how concerning is it to you that there is growing anger toward the united states in this region from arab countries, especially with fears looming this might grow into a broader conflict? >> i think the united states and its allies have to do a better job on the communication aspect. that's what that was all about, and that diplomat was really acting as a switch. i understand he's communicating or they're communicating back to the united states. but at the end of the day, they have to do their job and push back on this fight and recognize that israel is fighting for their existence and fighting for something that after being attacked, so again, as i look at those communiques, it's unfortunate they're leaking but i don't think they're going to put pressure on israel yet. they're not going to stop until hamas has been roundly and soundly defeated. >> one way the united states is sending a message is putting u.s. personnel in the region, in the form of carrier strike groups and actual troops stationed not far from where we're seeing combat. i'm wondering, nearly 60 u.s. service members have been injured by iranian backed groups since the start of this war about a month ago. is the deterrence that's in place by the united states now enough? >> it's in my view that the deterrence is mostly visual and it's not enough. if i was the parent of a service member that was in syria or inside of iraq and they were being attacked by these drones, i would say it's time to get them out. if we're not going to protect them like we should, it's time to withdraw them. what i mean by that is responding proportionally, going after the leaders of these groups attacking our soldiers. not some m.o. depots and dumps and the like, and not taking away their equipment. taking away the leadership making the decision. i would like to see the deterrence escalated. this administration does not want to see that because it could eventually lead to something they do not want to do with the iranians. we have to do more than just visual deterrence which is what we're doing. >> effectively, your argument is that iran needs to be confronted fundamentally because they're backing these groups and you know if these leaders are eliminated, iran isn't going to just sit by as it happens, are they? >> well, let's see what happens. let's see what they did last time. that's how it's supposed to work. so if they want to escalate, if they decide that it's important for them to escalate, we'll see what happens. then you'll see the true effect of having two carrier groups inside the mediterranean like we do right now. again, we have to insure, we don't want this to escalate, but protection of our forces has got to be one of our primary objects if not the primary objective and making sure we protect the troops. if we can't, let's get them out of there and not put ourselves into that fight. >> major, we appreciate your time and perspective. >> thanks. still to come, president biden taking credit for democrats' big week and also downplaying some bad polls. plus, suspicious and potentially dangerous letters at election offices. we have details on the fbi's investigation. later, the irs announcing new income tax brackets for 2024. what this means for your wallet. all that and much more still to come on cnn news central. . joe biden is officially on the 2024 presidential ballot in south carolina. today, vice president kamala harris traveling to the palmetto state to file that paperwork. this is a big deal because for the first time, south carolina will lead off the democratic primary calendar. >> it also carries historic significant for joe biden. it does come at a time where the president is taking a victory lap over democrats' success in elections this week and as he's taking a jab at donald trump. biden saying at a fund-raiser, we haven't stopped winning and he hasn't stopped losing. the truth is, this guy can't get tired of losing. biden also downplayed the cnn and "new york times" polls that showed him trailing trump in several key states in a hypothetical rematch. jeff zeleny and david chalian join us. it seems like a more aggressive tone from the white house. >> it definitely is a more aggressive tone. he's trying toshow he's in the game. that he's not only president but also a candidate for president, and he wants to show a little bit of bravado here. it's clear that he has been sort of disheartened and angered by just this narrative that is setting in that he's in a head-to-head matchup with the former president and that he's down in all these polls. he's been through many elections and he's been down in many elections. he's lost a few elections. but he's won a key election as well. just trying to show she's he's a candidate for president as well and taking jabs at donald trump. he seemed to relish in that. all of this is to show it's a choice between the two of them. it's not just all on him. >> to that point, does the president have a point, hey, we're still really far out in the election? and sort of to that point, it's sort of what jim clyburn is saying. people are not in sync with the campaign yet. he used that word, and he said you look at bill clinton. you look at barack obama, they weren't with those incumbents either. so i guess he's saying they'll come around. but is the president correct, we just have time here? >> he's certainly correct. we're a year away. a poll a year out from the election is not election results. he's certainly correct on that, but as we sat here earlier this week, and the vice president came out in the aftermath of the polls and tuesday's election results to go before the cameras at the white house earlier this week, she said the president and i have our work cut out for us, and we have work to do. and they do have work to do. so yes, are these poll headlines welcome developments for the biden campaign? no, of course not. are they just a snapshot right now and kind of identify what the work is ahead? key parts of the president's coalition that delivered him to the white house in 2020, young voters, african american voters. hispanic voters. there's clear diminishment of support. that doesn't mean that's where it will end up but it does mean they have work to do. >> we have seen biden pull off comebacks before, notably in south carolina. he lost in iowa, lost in new hampshire. that state turned his fate around. now it's the first one in the primary process for democrats. that's significant. >> it is significant. the reason it's first is he lost in iowa and new hampshire. the white house and dnc decided to wipe them off the map of the early calendar because they were afraid of the potential of a primary challenge. and there are a couple small primary challenges out there. dean dean phillips, the congressman, but by starting in south carolina, he will likely not have a big challenge to his candidacy there. otherwise, the significance of south carolina is largely symbolic. of course, it doesn't play a role in the general election. it's not too competitive at this point. i think it's interesting that the vice president went down there. she's becoming much more engaged in this race as well. she has been out campaigning at hbcus and certainly on the abortion issue. >> what does the president need to do to build off these wins? these recent election wins? >> well, i do think you're going to see, and we have seen, and you're going to continue to see a leaning in to this fight for abortion right. i think you're going to see a continued effort on this notion of the democracy being at stake to get to jeff's point about this has to be a choice. that is at the end of the day what the biden team is really banking on here, is that once this is a fully engaged, fully funded, one-on-one battle between the sitting president and the former president, that that contrast benefits them. and that is what they're counting on. the context isn't quite there yet. we have to get through even though he's the dominant front-runner, the republicans still have to vote in this process. but once that arrives, the white house believes they're going to be in a better position to make the contrast campaign. it's not just about selling bidenomics. that is clearly not it. they're going to have to explain why the alternative is bad for the country. >> this is the preparty. the real show is still a ways off. >> never mind a third party. >> nice one. that was good. that was practically a mom joke. i'm going to steal it. jeff and david, thank you so much. and coming up, who sent these suspicious letters to election offices in six different states? that is what the fbi is trying to find out, as at least one letter was lacaced with fefenta. c'mon, we're right there. c'mon baby. it's the only we need. go, go, go, go! ah! touchdown baby! -touchdown! are your neighbors watching the same game? yeah, my 5g home internet delays the game a bit. but you get used to it. try these. they're noise cancelling earmuffs. i stole them from an airport. it's always something with you, man. great! solid! -greek salad? exactly! don't delay the game with verizon or t-mobile 5g home internet. catch it on the dear moms and dads,. what you have achieved here today is going to help us and our futures. it is why we're coming up on stage to collect your diplomas. mom, love you always. vo: when you graduate, they graduate. visit finishyourdiploma.org to find free and supportive adult education centers near you. federal investigators are trying to hunt down whoever spent suspicious letters to election offices in several states. one official says their letter contained fentanyl and it's suspected to be in other letters too. investigators believe all the incidents were connected given the timing. josh campbell joins us now. what's the latest on the investigation? >> reporter: boris, at this hour, authorities have not announced any suspect they're looking at, but we're talking about an investigation that involves several different agencies. at least six different states here, letters sent to election officials in california, georgia, nevada, oregon, texas, and washington state. we did get a statement in from the federal bureau of investigation. they say that the fbi along with our law enforcement partners responded to multiple incidents involving suspicious letters sent to ballot counting centers. and is reminding everyone to exercise care in handling mail, especially from unrecognized senders. if you see something suspicious, please contact law enforcement immediately. it's important to point out just for perspective here, speaking this morning with a medical professional who specializes in fentanyl overdoses. we're not talking about anthrax here, which is very deadly in low quantities, but fentanyl, if you have a casual inhalation of that, according to this official, the ability to die from that is very low. so we just want to tamp down any possible hysteria here, but obviously, if you're an election worker out there, you're in fear because these letters are coming to your place of business. i expect we'll likely see serious charges if and when this person is taken into custody. not only interstate threats in the mail, but interfering with the electoral process. >> you're a former fbi specia