Shots have been fired at sit-in outside of the building where ousted leader Mohammed Morsi is thought to be being held. This came just hours before the interim government was expected to name a new premier.
At least 15 people, including an army officer, died early on Monday when shots were fired on a demonstration outside of the Republican Guard barracks in Cairo, according to the Muslim Brotherhood. The military has been holding Morsi there since removing him from power last week.
The Muslim Brotherhood blamed the deaths on Egyptian security forces who had been attempting to disperse the crowd.
Military officials speaking on the condition of anonymity said the violence began when an unidentified group attempted to storm the building. However, they have not confirmed who was responsible for the casualties.
Several people were killed at the same site late last week.
Egypt awaits new premier
Reports of the early morning violence came hours before the country's interim government, which took office following Morsi's removal, was expected to announce a new caretaker prime minister.
The Islamist el-Nour party has so far objected to two liberal-minded candidates put forward by the transitional administration. The ultraconservative Salafi party has signed up to the army's transition plan, giving it leverage over the choice of the next prime minister.
On Saturday, interim President Adly Mansour's office went back on a decision to appoint opposition leader Mohamed ElBaradei to the prime minister's post, following an objection by el-Nour. The group says ElBaradei, a Nobel Peace Prize winner and top opponent of Morsi, would have been a divisive premier.
Early on Monday, the news agency AFP quoted Mansour's media advisor, Ahmed al-Muslimani, as saying the president favored appointing center-left lawyer Ziad Bahaa Eldin as prime minister and ElBaradei as vice president.
However el-Nour has also refused to back Eldin as prime minister, because he used to belong to ElBaradei's National Salvation Front coalition.
"We don't object to [Eldin] personally, he is an economic pillar," the party's head Younes Makhyoun told the Al-Arabiya television channel.
"We reject his candidacy because he belonged to the National Salvation Front," he said.
"Our position is that the prime minister should not belong to a specific faction...We want a technocrat," Makhyoun told the Associated Press.
The news comes after tens of thousands of protesters again flooded Egyptian streets on the weekend, in rallies in support of and against Morsi. Thousands of supporters are camped out in a suburb of northeastern Cairo, and have refused to move until the former president is reinstated.
Opponents of Morsi's Muslim Brotherhood called for a demonstration of support for the military handover in the city's Tahrir Square on Sunday. Air force jets flew above the square, drawing a smoke trail representing the Egyptian flag in the sky.
The Tamarod movement, which staged the June 30 rallies that resulted in Morsi's overthrow, urged people to gather at Tahrir and the Ittihadiya presidential palace to "complete the revolution."
The military deployed troops at points throughout the capital, amid fears of violence between the two groups. An army statement warned against "provocative actions," vowing that violations would be "dealt with decisively, under the law."
Although the Brotherhood has refused to take any part in the new political system, ElBaradei has called for the "inclusion of the Brotherhood in the democratization process."
"No one should be taken to court without a convincing reason. Former President Morsi must be treated with dignity," he told Germany's Spiegel weekly.
German Foreign Minister Guido Westerwelle on Sunday said that German support for the new administration depended on a return to democratic transition.
"This is the standard by which we will judge the new government in Cairo," said Westerwelle. "The more clear the democratic transformation becomes, the more committed Germany will be in its support."
jr,kms/pfd (Reuters, AFP,dpa)