Tensions remain high in Cairo after the shooting of dozens of supporters of ousted president Mohamed Mursi.
Tanks are out on the streets and have blocked access to the military barracks where the shootings happened.
Initial reports spoke of 42 dead, the head of the city’s emergency services later said 51 people had been killed.
The Egyptian military has said a “terrorist group” tried to storm the building.
The Muslim Brotherhood claim its supporters were fired on while they were outside the headquarters of the Republican Guard.
Egypts interim leader expressed “deep regret” about the deaths and urged protestors not to apprach military buildings. The state news agency reported that the interim head will form a judicial committee to investigate the events.
However, a presidency spokesman Ahmed Elmoslmany said, “What happened will not stop steps to form a government or the (political) roadmap.”
Demonstrator Mohamed Adli accused the Muslim Brotherhood of killing their own members, saying: “It must be they themselves, no one from here would go and open fire there. It is someone from the Muslim Brotherhood so they can say the police and the army are killing the supporters of Mohamad Mursi.”
Adli continued, “This is the way they think, they would kill themselves, so they can say the army and the police and the people are all rotten!”
The Muslim Brotherhood has declared that the armed forces chief wants to drive Egypt to the same fate as Syria.
In Tahrir Square, anti-Mursi protesters have begun to congregate again.