Egypt's Muslim Brotherhood movement was set to carry out nationwide protests Friday against the military coup that deposed Islamist President Mohammed Morsi.

The largest demonstration was to be held in Raba El-Adwyia mosque square in the Cairo district of Nasr City, where Islamist supporters of Morsi - who was democratically elected a year ago - have staged rallies in recent days.

Brotherhood spokesman Ahmed Aref urged Morsi's backers to march peacefully, while also calling on state institutions to guarantee their safety.

The National Alliance in Support of Electoral Legitimacy, which comprises the Brotherhood and other groups, has called for Morsi - a senior member of that movement until shortly before assuming the presidency - to be returned to power.

Morsi's Islamist supporters have held protests since Wednesday's coup, when Egypt's armed forces suspended the constitution and named Adli Mansour, the head of the Supreme Constitutional Court, as interim head of state pending fresh elections.

Authorities will also appoint a panel of experts to amend the constitution that Morsi enacted during his abbreviated term in office, the country's military chief, Gen. Abdel Fattah al-Sisi, said Wednesday.

The military carried out the coup following days of massive anti-government protests.

Critics accused Morsi and the Brotherhood of doing little to address poverty and Egypt's struggling economy, of failing to advance the goals of the 2011 revolution that forced out strongman Hosni Mubarak and of seeking to monopolize power.

Morsi's whereabouts is unknown, although the Muslim Brotherhood says he is being held incommunicado by the military.

For its part, the "Tamarod" (rebellion) campaign that led last Sunday's protests demanding Morsi resignation has organized a demonstration for Friday in Tahrir Square and the Ittihadiya presidential palace in Cairo.

The goal is "to protect the revolution," according to that grassroots movement, which claims the military coup marks a new phase in a political transition that was derailed under Morsi.

On Friday, Egypt's armed forces called on Egyptians to leave aside desires for revenge and work to achieve national reconciliation, while also guaranteeing freedom of expression and assembly.

In a message posted Friday morning on the Facebook page of army spokesman Col. Ahmed Mohammed Ali, the military warned protesters not to commit any acts of sabotage or attacks on public or private property, saying those actions would represent a "threat to social peace and the nation's interests."

The message, however, held out an olive branch to the Brotherhood, saying the military would not take "any exceptional or arbitrary measures against any political group or movement."

That statement was issued in the wake of the arrest of the Brotherhood's top leader, General Guide Mohammed Badie.

On Friday, the army declared a state of emergency in the southern part of the Sinai Peninsula after several attacks by armed groups on security checkpoints. EFE