gunfire. medics treated wounded on the pavement under the street lamps. by midnight, the opposition still controlled cairo's bloody tahrir square. ivan watson, cnn, cairo. >> ivan joins us live where light is starting to break, dawn is coming up. are they preparing from what you can see, are they preparing for what they be more attacks? >> reporter: they've been preparing basically since the fighting began, anderson. they've been digging up, as you saw in that report, digging up stones to use for ammunition. barricading the entrances to this place and trying to keep morale up, swearing they're going to fight back. the sound of the picks digging into the asphalt all night, it's uncanny, as well as the sound of the wounded and the prayers. i can only compare it to perhaps a medieval siege would have sounded like around a castle.