Egypt's presidency has ordered the formation of a judicial committee to investigate the clashes that took place in the early hours of Monday between supporters of deposed president Mohamed Morsi and the armed forces.

The presidency expressed its deep sorrow for the fallen victims in what it described as "an attempt to raid the Republican Guard headquarters."

The statement stressed that everyone is guaranteed the right to protest, however it called on protesters to remain peaceful and avoid approaching vital institutions and military establishments.

At least 42 people were killed and 300 injured in violent clashes on Monday morning between Morsi supporters and the army. Morsi’s Muslim Brotherhood claimed that a peaceful pro-Morsi sit-in was attacked by the military during dawn prayers, while the military stated that an "armed terrorist group" attacked the Republic Guard headquarters, leading to the deaths.

The army claimed that the attack left one officer killed and 40 soldiers injured, in addition to seven in critical condition.

A military source told Al-Ahram Arabic news website that the armed forces are urging all citizens to remain peaceful and to not approach any military establishment, stating that they will strongly confront any assault against military or sovereign institutions.

The Muslim Brotherhood has been leading a sit-in for several days in front of the Republican Guard headquarters to demand the return of deposed president Mohamed Morsi. Several pro-Morsi protesters were shot on Friday in clashes with security forces at the same location.

Initial investigations by the prosecution found remains of Molotov cocktails and bullet and birdshot casings at the site of the clashes.