At least three people are dead and around 1,000 have been injured after anti-Israeli sentiment and frustration at the pace of change boils over into violence in Cairo.
There were disturbances across the Egyptian capital after police fired tear gas at hundreds of protesters who tried to stormed the Israeli embassy.
US President Barack Obama and Prime Minister David Cameron called on Egypt to honour its international obligations to protect Israeli diplomats after crowds who had been demonstrating in Tahrir Square smashed through a wall protecting the embassy building on Friday.
Demonstrators used hammers, large iron bars and police barricades to tear down the wall, which was erected this month by the Egyptian authorities after daily protests over the killing of five Egyptian border guards in Sinai.
Security officials said group of about 30 protesters began dumping hundreds of Hebrew documents from a balcony. Others managed to climb up and pull down the Israeli flag for the second time in less than a month.
Sources said the mob breached the exterior of the compound but failed to break into the main embassy building, in a tower overlooking the Nile.
Egyptian police made no attempt to intervene for several hours.
But police and soldiers later fired tear gas and blanks after protesters threw firebombs and pelted them with stones. Around 1,000 people were reported to have been injured in the clashes, with 38 still in hospital.
Relations between the Jewish state and its Arab neighbour plummeted earlier this month when Israeli forces killed the five border guards in an operation against gunmen who had killed eight Israelis.
Egypt threatened to withdraw its ambassador from Tel Aviv, but Israel has refused to apologise, saying it is still investigating how the Egyptian troops were killed.
Anti-Israeli sentiment has surfaced among Egyptians and calls to end an historic 1979 peace treaty with Israel have grown louder.
Anger over the incident comes amid continuing political unrest in Egypt, seven months after the popular uprising that ousted former president Hosni Mubarak.
Israel will continue to hold fast to the peace accord with Egypt. Benjamin Netanyahu
Egyptians are pressing for urgent reforms, including more transparent trials of former regime figures accused of corruption, and for a clear timetable for parliamentary elections.
Thousands had converged on Tahrir Square, the centre of the pro-democracy protests that toppled Mubarak, after Friday prayers for what was billed as a “Correcting the Path” protest.
Israeli Prime Minister Benjamin Netanyahu, said he hoped to see staff who were evacuated from the embassy return to Egypt in the future.
He said: “Israel will continue to hold fast to the peace accord with Egypt. We are working together with the Egyptian government to return our ambassador to Cairo soon.
“I would like to ensure that the security arrangements necessary for him and for our staff will be steadfast, and will provide them with the required security.”