Amid fears of imminent civil war, Egypt’s Muslim Brotherhood called Monday for an “uprising” against the military and urged international intervention in Egypt to prevent the situation from spiraling out of control.

The call to arms came hours after some 40 members of the Islamist group were killed in a clash with the Egyptian military, according to numbers released by the Egyptian Health Ministry. Hundreds more said to have been injured.

The Egyptian interim government expressed “deep regret” for those killed in the violence, saying the deaths were a consequence of protesters attempting to attack Cairo’s Republican Guard headquarters. The administration said in a statement on state TV that a committee was formed to investigate the incidents.

In the face of “those trying to steal their revolution with tanks,” the only option open to “the great people of Egypt” is insurrection, the Muslim Brotherhood’s political arm said in the statement, AFP reported.

The Brotherhood further called on “the international community and international groups and all the free people of the world to intervene to stop further massacres… and prevent a new Syria in the Arab world.”

A separate statement posted on the party’s website Sunday decried the “full military coup d’état masterminded in the dark to crush democratic legitimacy,” while asserting that the Muslim Brotherhood was committed to a nonviolent resolution of the crisis.

“We will not stretch our hands to harm anyone of those who attack us,” the statement said. “We will not be a party to shedding of Egyptian blood, even if others shed our blood, we will meet bullets and weapons with only bare chests and empty hands.”

Also on Monday, two Egyptian army soldiers were kidnapped on the street by armed Morsi supporters and forced to make pro-Morsi statements on a car loudspeaker, according Egyptian state media cited in an AFP report. The two soldiers, one of whom was beaten up, were later able to escape from their assailants.

A Muslim Brotherhood activist said to have been injured in clashes Monday, July 8, 2013 (photo credit: Gehad El-Haddad/Muslim Brotherhood, via Twitter)

A Muslim Brotherhood activist said to have been injured in clashes Monday, July 8, 2013 (photo credit: Gehad El-Haddad/Muslim Brotherhood, via Twitter)

Earlier Monday, Muslim Brotherhood activists clashed with soldiers outside the headquarters of the Republican Guard in Cairo, where they believed that ousted president Mohammed Morsi is being held under arrest. The army said they had killed an officer and critically injured several soldiers.

Citing the military, Egyptian state television reported that the soldiers opened fire in response to a “terrorist” attack on the compound, which has been the target of previous attempts by Muslim Brotherhood supporters to free Morsi. On Friday, at least four activists were killed by army fire there.

The military said it had arrested some 200 people and seized weapons, ammunition and Molotov cocktails. It confirmed that at least five pro-Morsi activists had been killed in the exchange.

Satellite broadcaster Al-Jazeera showed footage from a nearby field hospital of at least six dead bodies laid out on the ground. A medic from the area, Hesham Agami, said ambulances were unable to transport more than 200 wounded to hospitals because the military had blocked off the roads.

Al-Shaimaa Younes, who witnessed the incident, said military troops and police forces opened fire on the protesters during early morning prayers. “They opened fire with live ammunition and lobbed tear gas,” she said by telephone. “There was panic and people started running. I saw people fall.”

Women and children had been among the protesters, she said.

Citing the “massacre” at the Cairo compound, al-Nour, the ultraconservative Salafist Islamist movement, announced that it was pulling out of the bloc of factions that have been wrangling over who will fill the prime minister’s spot in the interim government. 

The Associated Press contributed to this report.