The United Nations Security Council has called an urgent meeting to discuss the situation in Egypt. The announcement follows the Egyptian government's approval of deadly police force in the country's ongoing crisis.
The closed-door Security Council session, scheduled for late on Thursday, was called for by France, the United Kingdom, and Australia, according to media reports.
The Interior Ministry Thursday authorized the police to use deadly force to protect themselves and state institutions, and said the government would confront "terrorist actions and sabotage" allegedly carried out by ousted President Mohammed Morsi's Muslim Brotherhood group.
In Giza, which lies on the west bank of the Nile River across from Cairo, pro-Morsi protesters allegedly attacked government buildings. There were also reports of a fire at the site, although it was not immediately clear how much of the building the blaze had affected.
The violence came as Cairo braced for a march and the possibility of more clashes between the military and supporters of ex-President Mohammed Morsi. The Muslim Brotherhood announced the demonstration on Thursday, a day after security forces cleared two of their camps.
"Marches are planned this afternoon from Al-iman mosque to protest the deaths," the group said in a statement.
Security forces swept through their makeshift camps including in Nasr City near Cairo's Rabaah al-Adawiya mosque. Egypt's health ministry raised death toll figures on Thursday to 578, saying that 228 of the casualties were from the main camp in Nasr City alone. However, the Muslim Brotherhood claims the death toll surpassed 2,000.
The interim government declared a month-long state of emergency following the violence. On Thursday, the curfew hours were reduced by two hours to start at 9:00 p.m. rather than 7:00 p.m., a cabinet statement said.
Other cities in Egypt saw more unrest overnight. Brotherhood members allegedly attacked the finance ministry building, police stations and several churches belonging to Egypt's largely Coptic Christian minority, according to the interim government.
UN: Crackdown 'excessive'
The United Nations right chief Navi Pillay called for an investigation into the forced removal of Morsi supporters.
"The number of people killed or injured, even according to the government's figures, point to an excessive, even extreme, use of force against demonstrators," Pillay said in a statement on Thursday.
"There must be an independent, impartial, effective and credible investigation of the conduct of the security forces. Anyone found guilty of wrongdoing should be held to account," she added.
US cancels joint military exercises
International leaders have condemned the government's efforts to uproot Morsi supporters.
US President Obama announced in a radio address the United States would not participate in a joint military exercise with Egypt slated for next month. Washington's relationship with Cairo could not go on "as usual" in light of the killing of civilians in the streets, he added.
Turkish Prime Minister Recep Tayyip Erdogan called for action from the United Nations Security Council on Thursday while speaking to reporters in the Turkish capital Ankara.
"Those who remain silent in the face of this massacre are as guilty as those who carried it out," Erdogan said. "The UN Security Council must convene quickly."
Western leaders criticized Egypt's interim government for allowing forces to sweep through the camps.
German Foreign Minister Guido Westerwelle, on an official visit to Tunisia, called the Egyptian ambassador to the foreign office in Berlin on Thursday.
"A spiraling escalation of violence cannot be allowed to start now," Westerwelle said in Tunis.
French President Francois Hollande on Thursday morning also summoned the Egyptian ambassador in Paris.
Egyptian Vice President and Nobel laureate Mohamed ElBaradei resigned on Wednesday evening due to the violence. He said the loss of life troubled him, "particularly as I believe it could have been avoided."
kms/dr (AP, AFP, Reuters, dpa)