As the world watches events in Egypt unfold, there has been swift reaction, with many countries expressing their grave concern and calling for an end the violence.
There has also been condemnation of what many governments see as the "disproportionate use of force " by the security services.
Most countries have called for restraint from both sides.
Scores were killed on Wednesday when security forces cleared a camp of protesters who were demanding the reinstatement of deposed president Mohamed Morsi.
US Secretary of State John Kerry called the violence "deplorable", saying it delivered "serious blow" to reconciliation efforts.
Meanwhile, White House spokesman Josh Earnest urged Egypt's military-backed authorities to respect the basic human rights of the Egyptian people and said the US strongly opposed Cairo's declaration of a one-month state of emergency.
United Nations Secretary General Ban Ki-moon condemned a police crackdown on protesters in Egypt that he said had left hundreds dead and injured.
"In the aftermath of today's violence, the secretary-general urges all Egyptians to concentrate their efforts on promoting genuinely inclusive reconciliation," his spokesman Martin Nesirky said.
While the UN was still gathering information, Nesirky said "it appears that hundreds of people were killed or wounded in clashes between security forces and demonstrators".
The European Union also called for restraint from Egyptian authorities.
"We reiterate that violence won't lead to any solution and we urge the Egyptian authorities to proceed with utmost restraint," Michael Mann, a spokesman for EU foreign policy chief Catherine Ashton, said.
The Palestinian movement Hamas also disapproved Egypt's "terrible massacre".
Turkey's Prime Minister called on the UN Security Council and the Arab League to take immediate steps to stop a "massacre" in Egypt, saying international silence had paved the way for the Egyptian authorities deadly crackdown.
"The international community, especially the UN Security Council and Arab League, must act immediately to stop this massacre," Erdogan's office said.
Qatar also condemned the attack by security forces, with QNA, the state news agency, quoting a foreign ministry official as urging Egyptian authorities to "refrain from the security option in dealing with peaceful protests, and to preserve the lives of Egyptians at protest sites".
Qatar had strongly backed Morsi, who belonged to the political wing of the Muslim Brotherhood.
Iran, also calling the security operation a "massacre", condemned the actions of Egypt's security forces, saying the violence increased the likelihood of a civil war there.
The Iranian Foreign Ministry said in a statement that Iran, "while denouncing the violent clashes and condemning the killing of people, expresses its deep concern regarding the horrible consequences".
"Undoubtedly the current approach to developments in Egypt strengthens the likelihood of civil war in this great Islamic country," it said.
France's Foreign Ministry issued a statement "strongly deploring the violence which took place in Cairo during the evacuation operations".
It offered its condolences to the families of the victims, and said it is "essential this violence ceases, and that a logic of appeasement prevails".
Follow our ongoing coverage of the political crisis in Egypt
"France calls on all parties to exercise the utmost restraint and warns against disproportionate use of force."
Britain issued remarks condemning the use of force and calling for restraint from security forces.
"I am deeply concerned at the escalating violence and unrest in Egypt," William Hague, UK foreign secretary, said in a statement.
"I condemn the use of force in clearing protests and call on the security forces to act with restraint."
Guido Westerwelle, Germany's foreign minister, urged supporters of Egypt's interim government as well as supporters of Morsi to renounce violence.
"We call on all political forces to return immediately to negotiations and avert an escalation of violence," he said.
"All further bloodshed must be prevented."