While the sets of videos showed each side attacking the other, neither definitively showed how the attacks started.
At a news conference, military spokesman Ahmed Mohammed Ali said protesters started the battle, attacking the Republican Guard building and troops stationed there, firing live ammunition.
“Any law in the world allows soldiers to defend Egyptian security when confronted with live fire,” Ali said.
Supporters of Morsi, who have been staging a sit-in the eastern Cairo district of Rabaa since June 28, a few hundred yards from the Republican Guard building, said soldiers began attacking them in an effort to clear the area as they were praying.
Witnesses said the fighting began with tear gas, followed by gunfire.
Ahmed Abdullah, 40, was among those injured, struck with rubber bullets in the leg. Standing outside the mosque, Abdullah said he’d tried to go to the hospital but an ambulance worker warned him: “If I take you, the police will arrest you.”
“The officer was laughing while shooting at me and others as if he were hunting for birds,” said Abdullah, an oil worker.
State television displayed videos zeroing in on attackers shooting at the army and wounded soldiers being carried away.
The military said in a statement that “terrorist groups” had tried to storm the Republican Guard headquarters and military personnel had protected the entrance. The military said it had arrested 200 protesters and that dozens of its soldiers were wounded, six critically.
Doctors treating the wounded at the Medical Insurance clinic in Nasr City, a government-run facility, called it “a massacre.” Most patients were wounded in the head, neck and chest, doctors saidm as a growing list of the dead and injured was posted at the clinic.
Ismail is a McClatchy special correspondent.