International pressure is mounting on the interim government and supporters of ousted President Mohammed Morsi to end the bloodshed that has swept the Egyptian capital.
An emergency meeting of the UN Security Council called for “maximum restraint” from the government and its opponents the Muslim Brotherhood to bring an end to the spreading violence.
But the Muslim Brotherhood, which saw its protest camps bulldozed and set fire to by authorities, has called for protest marches on the streets of Cairo and a “day of anger” after Friday prayers, giving rise to fears of further turmoil.
At least 638 people have been confirmed dead after pro-government forces attacked two camps where Mr Morsi’s supporters had gathered to demand his reinstatement.
The UN Security Council members called for national reconciliation, expressed regret at the loss of life and sent sympathy to the victims of the bloodshed, but stopped short of condemning the violence.
US president Barack Obama is also facing growing criticism over his response to the crisis.
He cancelled a joint military exercise with Egypt, saying “our traditional cooperation cannot continue as usual”, but gave no indication that the US would cut its £830 million (1.3 billion dollars) in aid to Egypt.
But Republican senator John McCain told BBC’s Newsnight that the arrest of Mr Morsi had been a “coup”, and US aid should be withdrawn as a result.
He said: “The law is very clear that if there is a coup that aid is cut off and we decided not to do that.”
“It’s a great tragedy and the United States is basically an observer,” he added.
Egypt’s government issued a statement pledging that it would work on restoring law and order and expressing “sadness” for the deaths of Egyptians, the Associated Press said.
But it said it was facing “terrorist actions targeting government and vital institutions” by “violent militant groups”. It also warned that Mr Obama’s position, while “not based on facts”, could “empower the violent military groups”.
The Egyptian ambassador to London yesterday blamed supporters of Mr Morsi for the outbreak of violence in Cairo, suggesting the large death toll was partly due to reckless protesters killing each other.
Speaking at a press conference in central London, Ashraf El-Kholy expressed his “deepest regret” at the loss of life, but said the police and army had been forced to shoot at demonstrators.
“Of course they did nothing but return fire,” he said. “If you have somebody firing at you then you have to respond.”