Backers of Egypt's ousted president Mohamed Morsi pledged to stage daily demonstrations as they ended a day of angry protests in which over 80 people were killed on Friday.
The announcement came with Egypt already reeling from the deaths of 578 people on Wednesday when police cleared protest camps set up by loyalists of the deposed Islamist leader.
That crackdown drew strong condemnation from the international community, and EU foreign affairs chief Catherine Ashton called Friday for the bloc to adopt "appropriate measures" in response.
But Egypt's cabinet issued a defiant statement, saying it was confronting a "terrorist plot".
In Jordan, Morocco and the Palestinian territories, meanwhile, hundreds joined demonstrations in support of Morsi's Muslim Brotherhood movement.
The call to end the day's demonstrations came shortly after a night-time curfew went into effect.
"Today's rallies end with evening and night prayers (at about 1800 GMT), and will be followed by funeral prayers," Anti-Coup Alliance spokesman Gehad El-Haddad told AFP.
But he said the group of Morsi loyalists would hold "daily anti-coup rallies" going forward.
In the canal city of Suez, 10 people were killed by security forces and dozens injured when they gathered to protest in defiance of the curfew.
Their deaths brought to 83 the number killed in nationwide violence.
Earlier in the day, Morsi supporters emerged from mosques in the capital and elsewhere for "Friday of anger" protests.
Violence erupted almost immediately, with gunshots ringing out in Cairo and security forces firing tear gas.
In the capital, a man leapt off a bridge near a police station to escape shooting as police armoured vehicles advanced on protesters, witnesses said.
An AFP correspondent counted at least 19 bodies in one Cairo mosque, while witnesses said more than 20 corpses had been laid out in a second mosque.
Security sources and the health ministry reported at least 44 dead around the country, while the Muslim Brotherhood's political arm, the Freedom and Justice party, spoke of 130 killed in Cairo alone.
In the capital, streets were virtually deserted except for demonstrators and security forces, with the army deploying at key points in the city.
But some residents formed their own roadblocks, checking identity papers and searching cars.
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The interior ministry, which authorised police to use live fire if government buildings came under attack, accused the Brotherhood of attacking police stations, saying it foiled attempts to storm buildings.
And the cabinet accused the Brotherhood of a terror plot.
"The cabinet affirms that the government, the armed forces, the police and the great people of Egypt are united in confronting the malicious terrorist plot by the Muslim Brotherhood," it said.
Marches were also reported in the Mediterranean city of Alexandria, in Beni Sueif and Fayyum, south of Cairo, and in the Red Sea resort town of Hurghada.
Wednesday's crackdown on the protest camps has polarised Egypt, splintering the army-installed government and drawing forceful international condemnations.
The United Nations said it would dispatch Jeffrey Feltman, under secretary general for political affairs, to Cairo next week.
But Egypt defended the crackdown and announced it was cancelling naval exercises with Turkey to protest Ankara's condemnation.
Turkey, which backs Morsi, has recalled its ambassador to Cairo over the violence, prompting a tit-for-tat move by Egypt.
The EU's foreign policy chief said the violence was "shocking".
"I have asked member state representatives to debate and coordinate appropriate measures to be taken by the European Union in response to the situation in Egypt," said Ashton.
French President Francois Hollande on Friday discussed the crisis with counterparts in London, Berlin and Rome.
Germany said it would review ties with Cairo, and joined France and Britain in calling for EU talks on the situation, which are expected to take place on Monday.
On Thursday, the UN Security Council held an emergency meeting on Egypt, calling for an end to the violence and "national reconciliation".
President Barack Obama said the US was cancelling a joint US-Egyptian military exercise, but he stopped short of suspending Washington's annual $1.3 billion in aid.
The international response was not uniformly critical, with Saudi Arabia and Jordan saying they backed Egypt's fight against "terrorism".
King Abdullah said Saudi Arabia stood "with its Egyptian brothers against terrorism, deviance and sedition, and against those who try to interfere in Egypt's internal affairs".
The unrest pushed up oil prices on fears it could impact Suez Canal traffic or spark further Middle East unrest, analysts said.