After the police moved on the camps, street battles broke out in Cairo and other cities across Egypt. Government buildings and police stations were attacked, roads were blocked, and Christian churches were torched, Interior Minister Mohammed Ibrahim said.
At one point, protesters trapped a police Humvee on an overpass near the Nasr City camp and pushed it off, according to images posted on social networking sites that showed an injured policeman on the ground below, near a pool of blood and the overturned vehicle.
Three journalists were among the dead: Mick Deane, 61, a cameraman for British broadcaster Sky News; Habiba Ahmed Abd Elaziz, 26, a reporter for the Gulf News, a state-backed newspaper in the United Arab Emirates; and Ahmed Abdel Gawad, who wrote for Egypt's state-run newspaper Al Akhbar. Deane and Elaziz were shot to death, their employers said, while the Egyptian Press Syndicate, a journalists' union, said it had no information on how Gawad was killed.
The turmoil was the latest chapter in a bitter standoff between Morsi's supporters and the interim leadership that took over the Arab world's most populous country. The military ousted Morsi after millions of Egyptians massed in the streets at the end of June to call for him to step down, accusing him of giving the Brotherhood undue influence and failing to implement vital reforms or bolster the ailing economy.
Morsi has been held at an undisclosed location since July 3. Other Brotherhood leaders have been charged with inciting violence or conspiring in the killing of protesters.
A security official said 200 protesters were arrested at both camps. Several men could be seen walking with their hands up as they were led away by black-clad police.
The Brotherhood has spent most of the 85 years since its creation as an outlawed group or enduring crackdowns by successive governments. The latest developments could provide authorities with the grounds to once again declare it an illegal group and consign it to the political wilderness.