Three days of clashes between protesters and security forces killed at least 33 people and injured more than 1,500, the Egyptian Health Ministry said.
Officials said clashes Monday were sparked by a Molotov cocktail thrown at police, who responded by firing tear gas, rubber bullets and buckshot at demonstrators near the Interior Ministry.
"We were here, we were running away with an injured man, when we heard a shot and someone behind fell," Saieed, an oil industry worker, told the Financial Times. "One of us rushed to help him, but he too was shot down. I was planning to return to my job on Wednesday, but now I am staying so that their blood would not have been shed in vain."
A Health Ministry statement said deaths were reported in Cairo's Tahrir Square, Alexandria and Suez, the Egyptian Gazette reported.
Troops, seen as heroes by the Egyptian people when President Hosni Mubarak was ousted Feb. 11, led a new push to clear Tahrir Square, The New York Times reported.
At midday, thousands of protesters remained in control of the square and its side streets, the Times reported.
A makeshift hospital was set up in Tahrir Square.
An attempt to reach a cease-fire between protesters and authorities collapsed, the report said.
A week before parliamentary elections were to start the process of transition to a civilian government, the Supreme Council of the Armed Forces, which took over Egyptian rule after President Hosni Mubarak was ousted Feb. 11, expressed "sorrow" Sunday on its Facebook page for the violence. It said it ordered an investigation and asked the political parties to "contain the situation."
The council -- a military junta headed by Field Marshal Mohamed Hussein Tantawi, who served as defense minister under Mubarak -- said it remained committed to keeping the democratic transitional timetable. But it said nothing about its exit date, set for an unspecified time after a constitution is drafted and a president is elected, which could be in 2013.
Almost all civilian parties Sunday called for an end to military rule before the constitution's drafting.
Opposition leader and presidential contender Mohammed El Baradei told The Guardian he was ready to do anything to save Egypt from the deepening crisis.
"I think what we've seen ... is an excessive use of force, bordering on a slaughterhouse, against innocent civilians exercising their inalienable rights to demonstrate," he said.