EGYPT'S military rulers are facing international condemnation over the bloody crackdown on Muslim Brotherhood protesters, with France warning of the threat of "civil war" and Turkey demanding UN action.
At least 525 people were killed in Wednesday's assaults on two Cairo protest camps of supporters of ousted Islamist president Mohamed Morsi in the worst violence the country has seen in decades.
The United States led global condemnations overnight against the "deplorable" violence, while Paris, London and Berlin have summoned Egypt's ambassadors to voice their strong concern.
Turkey's Prime Minister Recep Tayyip Erdogan on Thursday called for an urgent UN Security Council meeting over Egypt's "massacre" of Morsi supporters.
China was characteristically muted, calling for "maximum restraint" from all parties, while fellow Security Council permanent member Russia only urged tourists to avoid trips to Egypt.
Only two Gulf states that have cracked down on Islamist groups within their own borders initially voiced support for the Cairo military leaders.
French President Francois Hollande said "everything must be done to avoid a civil war" in Egypt, while his government conveyed France's "great concern over the tragic events" to Egypt's envoy.
"France is committed to finding a political solution and calls for elections to be held as soon as possible, in line with the commitments made by Egypt's transitional authorities," said a statement.
Germany also summoned the Egyptian ambassador, a day after its Foreign Minister Guido Westerwelle urged all sides to renounce violence and return immediately to negotiations.
"On the orders of Foreign Minister Westerwelle, the ambassador was told the position of the German government in no uncertain terms," said a foreign ministry spokeswoman.
Turkey's Erdogan, a Morsi supporter, told reporters in Ankara that "the Security Council of the United Nations should convene quickly to discuss the situation in Egypt".
"This is a very serious massacre ... against the Egyptian people who were only protesting peacefully," he added, criticising "the silence" of the global community in the face of the bloodshed.
The United States did not initially criticise the overthrow of Morsi, Egypt's first democratically elected and Islamist leader, and has avoided using the term "coup," which under US law would have halted some $US1.3 billion in annual military aid to Cairo.
But US Secretary of State John Kerry's comments, in which he called for elections, appeared to fully recant his previously expressed support for Egypt's military-backed government.
"Today's events are deplorable and they run counter to Egyptian aspirations for peace, inclusion and genuine democracy," he said.
Denmark suspended aid worth four million euros to Egypt "in response to the bloody events and the very regrettable turn the development of democracy has taken", development aid minister Christian Friis Bach told the Berlingske newspaper.
Further afield, Pakistan expressed its "dismay and deep concern" over the loss of innocent lives and called the events "a major setback for Egypt's return to democracy".
The Philippines urged its 6000 nationals in Egypt to leave the country and raised the alert level because of "the escalating civil unrest and insecurity".
The United Arab Emirates and Bahrain separately voiced support for Egypt's military leaders, saying it was the state's duty to restore order.
The Emirati foreign ministry affirmed its "understanding of the sovereign measures taken by the Egyptian government after it had practised maximum self-restraint during the preceding period".
The Gulf state, where dozens of Islamists have been jailed for plotting to overthrow the regime, criticised what it said was the "insistence of political extremism groups to make speeches of violence and incitement ... that led to (Wednesday's) sad events".
Another Gulf state, Bahrain, which is facing an uprising led by the Shi'ite majority against the Sunni regime, said that the "measures taken by Egyptian authorities to restore peace and stability were to protect the rights of the Egyptian citizen, which the state is obliged to do".