JERUSALEM, Israel -- Tens of thousands of supporters of ousted Egyptian President Mohammed Morsi threatened to storm the military's Republican Guard headquarters Monday morning if Morsi were not released, over the weekend.
A confrontation also took place early Monday morning, with the Muslim Brotherhood claiming one scenario and the military another.
A Muslim Brotherhood spokesman said the military opened fire on unarmed men who were praying, killing 37 and wounding 300. Egyptian state television reported 42 killed.
The military, which is now in charge of the country, said soldiers only returned fire after some of the protesters fired on them as they tried to storm the building, saying one soldier was killed and at least 40 wounded in the firefight.
Meanwhile, the ultra-fundamentalist Salafist al-Nour party, which initially supported Morsi's ouster and appeared willing to work with the interim government, said it will no longer be part of negotiations because of Monday morning's "massacre."
The party reportedly convinced interim President Adli Mansour to reconsider appointing opposition leader Mohammed El Baradei as interim prime minister.
Meanwhile on Sunday evening, opponents of the former president filled Cairo's Tahrir Square to reaffirm that ousting him was the will of the people and not a military coup.
Also on Sunday, jihadists attacked five military checkpoints in Sheikh Zuweid near the border with Israel. Gunmen opened fire on security officers from pickup trucks, killing one Egyptian soldier and wounding a police officer, the Egypt Independent reported.
Gunmen killed five security officers Friday in the town of El Arish, about 30 miles from the Israeli border. On Saturday, jihadists killed a priest, blew up a gas pipeline to Jordan, and opened fire on at least four other military checkpoints in the northern Sinai.
Terror cells blew up the pipeline, which transported gas to Israel and Jordan, at least 10 times since President Hosni Mubarak was overthrown two years ago.
A group calling itself Salafi Jihadi said that "current events ravaging the country" were spilling over into the Sinai and vowed to fight what it called the "repressive" tactics of the military and police. It's reportedly the group's first direct threat against the military.