- Egyptian security forces stormed two pro-Morsy sit-ins early Wednesday morning
- The government and Muslim Brotherhood said scores of people had been killed
- CNN's Reza Sayah said it was the most bloodshed he'd seen over the past six weeks
- At one point, CNN's Arwa Damon came under fire while reporting from the scene
Egyptian security forces stormed two sit-ins orchestrated by supporters of ousted President Mohamed Morsy early Wednesday, bulldozing tents and escorting away hundreds of protesters, CNN correspondents say.
At a makeshift hospital, CNN's Reza Sayah described walking through the blood of the injured.
"We have witnessed scores of injured brought on stretchers before us. Many of them were in bad shape. It looked like many of them had been shot," he said. "I have personally never seen this much bloodshed in what, according to what we've seen over the past six weeks, had been a peaceful demonstration."
Egypt's interim government and Morsy's Muslim Brotherhood are reporting scores of people have been killed in what's being dubbed the country's bloodiest day since the 2011 revolution.
CNN correspondents described bloody scenes as security forces clash with Morsy supporters.
"I think what we're seeing right now is just the beginning of what is promising to be a very, very long and bloody battle as the interim government and the security forces try to regain control of the streets," CNN's Arwa Damon reported.
Arriving earlier at one of the entrances to the Rabaa al-Adawiya Square encampment, Sayah said the scene resembled "a war zone."
Thick plumes of black smoke were rising through the air from where it was understood security forces had entered the area and pro-Morsy supporters were facing off against those forces, he said.
Protesters were breaking bricks and gunfire could be heard, while tear gas was filling the air.
"Up above there are military helicopters and this is just an all-out fight and I think this is what a lot of people were concerned about -- this kind of violent scene," he said.
"There's heavy tear gas being used. A lot of people are emotional, we've seen women cry, we've seen people appear to lose consciousness because of the tear gas and now we just wait to see what happens.
"This is going to be an incredibly difficult demonstration to clear out. Not like (the Nahda camp) that was cleared out earlier today by security forces -- this is a much larger sit-in."
As Sayah spoke to CNN, he described protesters barricading the street where his television crew had arrived and where fighting had broken out.
It was unclear whether the clash had involved security forces or residents opposed to the sit-in, he said.
"That's not unusual for residents who are against the Muslim Brotherhood -- against the former president -- to get in on these fights."
The protesters appeared to be surrounded on all sides, he said.
"This is the most intense gunfire that I've personally heard during these clashes over the past six weeks. Clearly some of it automatic weapons, some of it sounds like it's coming from rooftops.
"I haven't seen any weapons on this side -- I haven't seen any protesters firing weapons but they are breaking bricks, throwing rocks -- it's not clear what they're throwing at. But there's a lot of chaos here."
Two hours later, Sayah said the outcome of the gunfight had been "incredibly bloody."
"Over the hours we've seen one body after another pass through to a makeshift clinic."
On the other side of the square, Damon said riot police had been firing tear gas "as groups of pro-Morsy demonstrators tried to break through police lines to join the encampment."
Military units could be seen behind the riot police, she said.
"At least four ambulances passed through the police lines on their way toward the site of the sit-in. Two members of the security forces could be seen being put into the ambulances."
Damon and her team later moved to another entrance to the square after experiencing some hostility.
"There were a few individuals in the crowd who were very anti-Western, anti-American, getting very aggressive toward the CNN team.
"Other individuals in the crowd were helping us to pull back from that situation," she said.
Damon and her team later came under fire while she was reporting live on CNN.
Three other journalists were later reported shot, two fatally, while covering the unrest. One of those killed was Mick Deane, a former CNN cameraman who had been working for Sky News for the past 15 years.
In the chaos of the raids, it has been impossible for CNN to verify the claims and counterclaims of protester casualties.
State TV reported that at least 149 people had been killed and more than 1,400 wounded.
The Muslim Brotherhood said earlier that 200 Morsy supporters were killed and more than 8,000 were injured. But the party has given exaggerated figures in the past, only to revise them later.