Begun bombarding gaza, cutting off electricity and water, and building up troops along the border. More than 500 palestinians have been killed in almost two and a half thousand strikes. Our International Editor jeremy bowen, has been following the days of intense violence. Inside gaza it looks every bit as if palestinians are feeling the full force of Israeli Military power. Israel says hamas is responsible for the suffering of gazas civilians. And its retaliation for the hamas attack is only just begun. Hamas has threatened to start killing its israeli hostages. The air strikes rolled on, hour after hour. Palestinian armed groups undeterred, kept up their own barrage of israel. Our bbc team was in ashkelon in southern israel not far from the gaza border when a salvo came in. Ashkelon is so close to guard so that there is no more than a ten second warning. Israel is moving in more fire power. The next stage of the offensive against hamas looks certain to be a Ground Offensive, much bigger than other incursions since hamas took over in gaza in 2007. Lines of cars outside a Military Base on the road to gaza were parked by reservists as they reported for duty, getting ready, saying their goodbyes. Parents came to the base for a few minutes with their sons. We are praying, and hope for the best. Amidst tough times now. And we are telling him to try and concentrate on his mission, without thinking too much about other friends that got injured or killed. Israels Prime MinisterBenjamin Netanyahu broadcast to his nation. Translation he said how mass has made a mistake l translation he said hamas has made a mistake of historic proportions. He said, be exacting a price that we be remembered by them and other enemies for decades. And now israelis are waiting for the government and army to act. The israeli town close to gaza littered with the debut of war felt like the essence of israels trauma, almost deserted except for forces. Hamas has rocketed sderot for years but has never before stormed in. At the centre of the hamas Killing Ground was the police station. They broke in and use it as a fire base to shoot civilians as well as soldiers. Blood from israels dead and wounded smears the walls. Even here in what is always a front line town, for israelis this was not supposed to happen. They expected their military, backed up by the intelligence services, to protect them. And the fact that didnt happen means recriminations, who might be responsible, ive already started. But at the same time there is a strong sense of national unity, of a country under attack, about what happens next. In the places that hamas attacked Israeli Military as well as the few civilians left are jumpy, still shocked. A Ground Offensive didnt feel imminent. And in gaza, a few miles away, casualties, into the main hospital. The first few hundred of many more. It will get worse. Palestinians and israelis once more caught on the anvil of war in a conflict a century old that is as deadly as it has ever been. Getting into gaza is incredibly difficult and dangerous. My colleague Rushdi Aboualouf is there now. Its not safe for him to broadcast live at the moment, so he sent this update this is by far the biggest ever israeli air strikes in gaza, on this scale, in this intensity. This is the biggest. In this building, its a Seven Storey Building where 20 to 30 families, they live in this building. I could hear the screaming of the kids, they were shouting. In the background, if you can see, its totally black. Most of the Electricity Supplies in gaza are not functioning, internet is down in every corner of this city. Talking about the humanitarian situation, gaza has been suffering for three days without electricity. The crossings, most of the crossings are closed except the rafah crossing with egypt, and it only allows people to go in and out no goods. No fuel is coming, no medicine for hospitals. The Health Ministry issued a Statement Today warning that within 48 hours the essential medical supplies are running out in the hospital. Nearby explosion. And they need urgent supplies to be able to provide services to many people. I could hear in the background israeli fighter jets are still flying overhead and targeting places between time to time and it seems that this night, the palestinians in gaza have never seen before. Rafell posh who is a spokesperson for united hatzal ah, israels National Volunteer ems organization, told me about the situation there. It about the situation there. Is been chaos which is saturday it is been chaos which is saturday morning, we were all broken up around 630 in the morning with the attacks in the Gaza Periphery in the right brushes in central israel. In the drizzling corridor and will be further north as well. And the rockets are fired and hundreds of people were killed, captured, kidnapped and atrocities and horrors are really we were thinking in the beginning. A member of our volunteers are injured and one was killed while trying to save lives as other people who were injured and when they were through israel. And the number of our organisation, many across israel who all drop whatever they were doing whenever there is a medical emergency, usually have a Response Time of less than three minutes and we are used to dropping whatever were doing in responding to emergencies at hand and we brought in 1500 volunteers across the country to the Gaza Periphery to provide humanitarian aid and medical services for both the civilians and Military Personnel involved in the attacks and that is been ongoing and continuing since saturday morning and bring in new volunteers into the home for rest and a couple of hours later, continuing to provide treatment and periphery, the transport so far we have over 1500 people and be transported in a helicopter and ambulances after stabilising the field and in central whenever we could take them and we are doing everything we can and sometimes going home to home in a town for people are told not to leave or exit their houses because it is too dangerous and bring them food and water medical supplies. And that is just a bit of what is going on in the home front which is continuous Rocket Brushes and in the island we had just a few years ago, a rocket landed in the town next was and we had to respond to that the number people were injured and so, it was a continuing conflict and only escalating at this point. And were doing the best we can to provide humanitarian aid to everyone who needs it. You said is an ongoing everyone who needs it. You said is an ongoing conflict everyone who needs it. You said is an ongoing conflict and everyone who needs it. You said is an ongoing conflict and that i is an ongoing conflict and that the situation that is rapidly unfolding as we continue to track it and how you are preparing for the potential for longer conflict as that is the prime apprehension at the moment . Prime apprehension at the moment . ,. , moment . Our first needs are purchasing moment . Our first needs are purchasing more moment . Our first needs are purchasing more medical purchasing more medical equipment and we have run out of our reserves even in the first couple of days of the conflict is because the massive amount of wood people up and having to treat and in addition to the regular medical emergencies across the country, we are creating a Campaign Repeat we can support us through our website and help support the initiative to provide medical care and again, this is not a denomination, were treating everyone in israel who needs it and we have donations from everyone were working to try to save lives and more equipment we have, the better we can protect her volunteers in the populace and treat the people were injured and get them as quickly as possible for definitive care. The more labs we can save. find the more labs we can save. And hamas as weve heard, hamas warned tonight that it will start executing Israeli Citizens held captive in gaza, if israel bombs more civilian houses in gaza without giving a prior warning. Some of those who were taken were pary go ers at a Music Festival. 0ur Correspondent Yolande Knell has been speaking to friends and families of those who are missing the israeli Dance Festival that turned into the site of a massacre. As many as 260 people were killed here, in the fields by gaza. Others were taken. This footage shows a hamas gunman who appears to be leading away a hostage. Palestinian militants say theyve seized 100 soldiers and civilians. These are the faces of some of the partygoers and others thought to have been seized. For ido dan, the horror� s been playing out on his familys whatsapp group. His relatives live next to gaza, and on saturday, his cousin hadas hid from hamas fighters in her home. She sent me this heart and she said. Im not sure were going to survive this. Hadas did survive, but five members of the family are now missing, including her 80 year old mother, her niece, two of her children and their father. This video appears to show erez, whos 12, being snatched. Ido pleads for their release. Just get him out of this confrontation. Its not for kids, its not for older people. I dont think there is any war ethics that were not violated here. Even war has rules and ethics and limits. As israel bombs gaza intensely, hamas says some hostages have lost their lives. And tonight its made a chilling threat, saying that each time israel strikes a palestinian home without first giving a warning, it will kill someone held captive. For the families desperate for news, fears are growing. Yolande knell, bbc news, tel aviv. Ariel cohen, who is a Nonresident Seniorfellow at the Atlantic CouncilsEurasia Center and a member of the council of foreign relations, gave us his thoughts on the developments. Im viewing the developments with extreme pain and heartbreak because we did not see anything like that. I hate to say it, since the holocaust, a thousand, close to a thousand people were murdered in one day on a high holiday. That is called joy of torahs torah, just like yom kippur 50 years ago. A huge failure of intelligence and defense by a country that prides itself for decades of being a leader in both fields and intelligence and in defense, and horrible atrocities in which children were executed in front of their parents, women and maybe not older women raped and old people as old as 80 and 85 in wheelchairs taking hostage. I have not seen anything like that, maybe with the exception of the atrocities committed by isis against the yazidis in the middle east. And of course, the surprise of 9 11 comes to mind. But in israel proper, nothing like that happened since the war of independence of 48. And if you compare it with the united states, it would take 27,000 americans to be killed in one day to compare it because israel is so much smaller than the united states. Right. Right, ariel. And of course, were also tracking casualties on both sides. In fact, on that note, israel has also announced a complete blockade of gaza. How worrying is it at the moment, in your opinion, for the civilians in gaza as the conflict escalates . What options of safety do they have . Israel announced seven safe zones, signaling the areas theyre not going to use for for the. So, israelis used to warn the civilians before knocking the buildings in which hamas locates deliberately using civilians as human shields. Where theyre located, their Missile Launchers and their command posts. But the biggest threat now is the escalation of the north, the north of israel. Escalation in which irans fully owned subsidiary, the terrorist organization hezbollah, may open a Rocket Barrage against israel. Hezbollah deployed over 100,000 missiles and rockets, much bigger in terms of range and warheads against israeli cities. And that may lead to an escalation against iran itself, targeting the iranian leadership and probably escalating to a non conventional level. Information from the white house which is categorically set the moment they have not seen any hard tangible evidence that iran was directly involved in the micro attacks on israel, how would you respond to that if the us is coming out with a Statement Like that . The if the us is coming out with a Statement Like that . If the us is coming out with a Statement Like that . The us is t in to Statement Like that . The us is trying to deescalate Statement Like that . The us is trying to deescalate and Statement Like that . The us is trying to deescalate and at i trying to de escalate and at the same time, the us is sending a carrier group, the biggest weapon in its arsenal, Eastern Mediterranean to warn syrian and iranian people that any escalation against israel from lebanon may result in a joint operation of the us and israel against iranian assets. Around the world and across the uk. This is bbc news. We learn how to take blood and deliver support for patients. As you can see, couple of what we use them here, quickly demonstrates him cpr. And we have two different things, this stimulates and encapsulates of been trying to do as part of our project for visual representation and within our curriculum and with the website shows in these conditions are different types and i am a third Year Medical Student and it is really important to be represented in people you know to be represented in health care as a means you have an equal level of confidence in being treated and you feel as though youre being respected. More than 40 of our students the Medicine Programme it is important for them to feel represented and seen and of the bigger picture, we need to make sure that our students are competent and confident to treat diverse populations in the uk. Youre live with bbc news. Israel has spent the day trying to regain control of parts of its territory in the south. Much of the activity has centred around ashkelon close to the border with the gaza strip. Anna foster has sent this report. Air raid sirens. Explosions. Theres a huge barrage going on overhead at the moment. We have taken cover. This is. Its actually a memorial building. You can see we are all here in the. There is nick, hes got the camera. Theres nick, hes got a camera. Yeah, were going to move. Get down, get down. We heard all around us but didnt know we were there. When the siren started, i was talking to gilad. He had been at the Music Festival where more than 250 people were massacred as hamas launched its attack on saturday morning. Shrapnel tore past his head. He was lucky to survive. The bullet went through here and through out here. So it went. Yeah, you can see it went in and out. Yeah. We got a fight orflight situation. You need to react really fast or that means you are dead, certain death. Its no wonder 250 people, 260 people died. And even more, i still dont know the body count. Explosions. People living here know these moments of fear well. Gilad and his mother didnt need words. We followed the smoke. We think this is where one of the missiles hit. Yeah, look. Here in the ground. In this poorer part of ashkelon, there arent bomb shelters in most buildings. Thin walls and windows dont stop missiles. So avi and anat hid their family in a stairwell. They told the children the explosions were thunder. We need to be strong for them, avi told me, but whos going to take care of us . Anna foster, bbc news, ashkelon. Injerusalem, the funeral of a british man who was killed on saturday while serving in the Israeli Military was interrupted by a nearby missile attack. 20 year old nathanel young, who moved to israel two years ago, died during the attack on the gaza border. From the funeral service, our correspondent nick nathanel youngs coffin was carried to mount herzl, israels national cemetery, where they grieved a londoner whod become one of their own. His family said it had always been his dream to be a frontline israeli soldier. More than 1,000 mourners turned out. Despite pleas to stay away, so the funeral itself would not be a target. Nathanel youngs sister started to pay tribute to him. Throughout the last 20 precious years, ive watched nathanel grow up from a cheeky little boy to a strong, brave, Kind National hero. But then, as she continued. Air raid siren. The solemnity was shattered. They took cover between gravestones and under trees, as explosions rang out. Some began reciting prayers. Before the alarm fell silent. We made our way to where one rocket seemed to have got through israels powerful air defences. This, an ultraorthodox settlement in an occupied palestinian area. This attack on a Community Nearjerusalem is a vivid illustration of how the situation has escalated so rapidly. We are far from gaza here, and as we speak there are more explosions that we can hear in the distance. One of many communities, both here and in gaza on the front line of this deepening conflict. Nick beake, bbc news, nearjerusalem. Speaking at a synagogue in north london, with the chief rabbi in attendance, uk Prime Minister rishi sunak expressed his solidarity with theJewish Community in britain and said he would work to make sure they felt safe. The United Kingdom stands of israel the United Kingdom stands of israel against