CAIRO - The sun was barely up Wednesday outside Nahda Square, where thousands of Egyptians had camped for days beneath party streamers and balloons in a protest against the ouster of president Mohammed Morsi.
Suddenly the small square near Cairo University became a killing zone.
"They came from all the three gates with tanks and helicopters and they started shooting tear gas," said Muslim Brotherhood leader Ashraf Abdel Ghaffar, who was in charge of the camp's makeshift infirmary.
Security forces with army support used a bulldozer to shove aside sandbags that protesters positioned in sturdy rows to block the square's main entrances from police and other intruders. Men entered the camp and started shooting, Ghaffar said.
In the melee, the infirmary erupted in flames as thousands of protesters tried to escape the bullets and the police who were arresting people.
Some ran to the nearby Giza zoo and a park near the sit-in, local resident Amin Abu Hashem told the Daily News Egypt. Those who stayed threw rocks at the advancing troops, who responded with tear gas, Hashem said.
Others dodged into a Cairo University building on the camp's fringe.
"We tried to save ourselves," Ghaffar said, who gave his account in a phone conversation from the university's faculty school of engineering.
He said he saw five people shot as they tried to hide, hit by snipers at the entrance. They died inside the building while two others had "massive bleeding."
The camp - once a bustling site where the protesters read the Quran, talked of politics and demanded the military reinstate Morsi - was destroyed before their eyes. Wooden tent frames that held up roofs of blankets and tarps were ruined. Posters of Morsi were torn down, people said.
Karim Goessinger, 26, an Egyptian-Austrian who could see one entrance of the sit-in from his balcony, said he was awakened by gunshots around 8 a.m.
"The streets were completely deserted," he said.
By then, about 2,000 men, women, children and more than two dozen wounded were hiding in the university. They remained there into the evening, Ghaffar said.
"We cannot go outside now because they are shooting us from everywhere and they are positioned from some high buildings," he said shortly after nightfall.
He said they were too scared to come out even though authorities promised protesters they could go home. "We don't want to be arrested," Ghaffar said.
It was unclear if protesters fired back from their hideout. Goessinger said Wednesday evening he heard gunfire throughout the day, although no one could say where it originated.
"Human rights organizations were monitoring the full process and there were weapons inside sit-ins," said interim Prime Minister Hazem El Beblawi in a news conference Wednesday. "We were surprised to see an attempt to spread chaos around the country."
State television broadcast infrared video images that they said show Morsi supporters firing on police.
"This is so unpredictable - what is happening here," Goessinger said.
The assault to take control of two sit-in sites came after weeks of warnings by the interim administration that replaced Morsi after he was ousted by the military July 3. The camps on opposite sides of the capital began in late June. The protesters - many from Morsi's Muslim Brotherhood - said they would not leave until Morsi was returned to power.
Amnesty International said its witness reports described a scene of unnecessary violence.
"Promises by the authorities to use lethal methods only as a last resort to disperse protesters appear to have been broken," said Philip Luther, director for the Middle East and North Africa program at Amnesty International.
"All too often in the past, the Egyptian security forces have used excessive force against demonstrators with catastrophic consequences," he said. "Security forces have a duty to prevent further loss of life. This must be an immediate priority."
Northward from the Nahda sit-in and across the Nile River, protesters outside the Rabaah al-Adawiya mosque said they were poised to hold their ground should the police try to move them. But they did not anticipate what would happen.
Protesters there said they made preparations the day before, readying several emergency hospitals and a central infirmary to receive any wounded. Sandbags and stone block walls were already fortified.
Wednesday morning, some in the encampment were reciting morning prayers; others were sleeping.
"We started to hear them shooting bullets and gas," said hardline Islamist Hesham al-Ashry who was awake when security troops appeared shortly before 7 a.m.
"They were dropping a lot of gas bombs," he said. "They were dropping them like crazy."
Al-Ashry said he grabbed a bottle of vinegar, then Coca Cola, dabbing liquid on his eyes and nose to quell the sting, gasping to breathe.
"They came from anywhere. Helicopters above us - the military helicopters - and the military soldiers came with the police. They came from everywhere, from all around, every direction," he said.
Al-Ashry said he darted back and forth with no real aim or way to escape as fighting persisted for hours.
"People are dying - women, children," he yelled over the phone at 10:30 a.m. Gunfire could be heard in the background. "I see snipers everywhere."
"Many times people would look to me and suddenly I'd find them with blood flowing out of their bodies," al-Ashry said.
Bodies filled an informal hospital-turned-local morgue. People with wounds were lined up in rows.
Heba Morayef of Human Rights Watch saw 34 bodies on a single floor, she said. A doctor told her all were killed with live ammunition and one burned in a tent.
The Health Ministry said Wednesday that at least 278 were killed in violence nationwide, including 43 police officers, among them two colonels and two major generals. That number was revised higher Thursday to at least 525 killed and 3,572 injured.
At the height of the chaos, black smoke billowed from the sit-in as protesters burned tires and other items, some said in an effort to weaken the sting of the tear gas. Nearby, some local residents who have been affected by the protests cheered the protest clearing.
Later in the day in the twilight hours, with fighting subsided, security forces moved the trapped protesters out through a single route.
The police and army "were screaming and yelling at us that we killed policemen," al-Ashry said. "I said, 'Mention the name of your friend that was killed. What is his name?'"
"They started to threaten us and said, 'If you don't stop, if you don't shut your mouth, we're going to kill you.'"
Mohammed Ibrahim, who is in charge of the Cairo police, said security forces cleared the Rabaa camp following international levels of self-restraint, with minimal causalities. He said Morsi's supporters stormed 21 police stations and damaged or torched seven churches nationwide.
At the end of the day, al-Ashry sat - dejected - at a mosque near the Rabaa sit-in. He didn't know where the leaders of the Muslim Brotherhood were, where to find the leaders of Gamaa Al-Islamiya - an Islamist group he supports - or anyone leading those backing Morsi.
"No one knows what happened," al-Ashry said.