Egyptian security forces opened fire at supporters of ousted President Mohamed Morsi, and clashes between the two sides have killed at least 42 people, the Health Ministry told Xinhua on Monday.

"Morsi's supporters were praying while the police and army fired live rounds and tear gas at them," the Muslim Brotherhood ( MB), from which Morsi hails, said in a statement earlier, adding that the supporters were demonstrating outside a military facility early Monday.

It said the initial death toll was 35 and would probably rise.

Calling on the international community to intervene to prevent the country from sinking into a Syria-style civil war, the group said "The blood of our martyrs builds our persistence to continue our peaceful protests against the criminals who made the coup."

Meanwhile, a statement posted on the official website of the MB 's Freedom and Justice Party (FJP) said the incident was a "human massacre" against peaceful citizens who protest against "a military coup" which ousted the elected president last week.

On Wednesday, the army forced Morsi's ouster after millions of people took to the streets to protest against the Islamist- oriented president's "poor performance" and "maladministration" since he came to power a year ago.

The FJP then urged for "an uprising by the great people of Egypt against those trying to steal their revolution with tanks" that crashed the Egyptian bodies.

However, the army said on state TV that one officer was killed and 40 wounded in the "attack" by Morsi's supporters on the military facility, while local media reported that two soldiers were kidnapped by some supporters of the MB.

Meanwhile, former ally of the MB, the conservative Salafists' Nour party decided to withdraw from talks with the government upon death of Morsi's supporters.

They agreed with the roadmap of the army but refused to accept Mohamed ElBaradei as interim prime minister.

In the face of opposition, Adli Mansour, who has been sworn in as the country's interim president, on Sunday recommended opposition leader ElBaradei as vice president and financial expert Ziad Bahaa-Eddin as interim prime minister.

Hours earlier, the MB announced that it was willing to accept initiatives for national reconciliation on the condition of Morsi' s return.

"Despite the bitterness we all suffer, the group is willing to accept the initiatives provided by sincere people who call for the return of complete legitimacy, including the president, the ( suspended) constitution and the (dismantled) Shura Council," the group said in a statement.

After Morsi's return, the statement continues, the president would run a national dialogue over disputed issues "to avoid bloodshed of the Egyptian people and to get the country out of the dark tunnel."

"The group will not compromise legitimacy and will not accept an alternative," the statement said, warning that the MB's members were willing to offer more sacrifices for Morsi and his legitimacy.

The statement referred to Morsi's ouster as "a conspiracy."