Fresh Egypt violence after crackdown kills more than 550

Fresh violence targeted the security forces in a tense Egypt Thursday, as Washington cancelled a joint military exercise in response to a crackdown on protesters that killed more nearly 600 people.

Security sources said at least seven soldiers and a policeman were killed in attacks in the Sinai peninsula, and another policeman was killed in the central city of Assuit.

With the country under a state of emergency and many provinces hit by night-time curfews, the interior ministry ordered police to take tough measures after a series of attacks on government buildings.

The death toll from nationwide clashes following Wednesday's operation to clear two protest camps in support of ousted president Mohamed Morsi rose to 578, making it the country's bloodiest day in decades.

International criticism of the bloodshed poured in, with diplomats saying the UN Security Council would hold an emergency meeting on Egypt at 2130 GMT on Thursday at the request of Australia, Britain and France.

The carnage prompted fierce international condemnation, led by the United States, with President Barack Obama announcing a joint US-Egyptian military exercise would be cancelled.

"While we want to sustain our relationship with Egypt, our traditional cooperation cannot continue as usual when civilians are being killed in the streets and rights are being rolled back," he said.

But despite cancelling the Bright Star exercise, which has been scheduled every two years since 1981, he stopped short of suspending Washington's annual $1.3 billion in aid to Egypt.

Meanwhile, the US State Department warned citizens not to travel to Egypt and called on those already there to leave.

In Europe, governments in multiple capitals summoned Egyptian envoys to voice their concern.

Earlier, Turkey's Prime Minister Recep Tayyip Erdogan, a Morsi supporter, had also called for an urgent Security Council meeting over Egypt's "massacre."

And UN rights chief Navi Pillay called for "an independent, impartial, effective and credible investigation of the conduct of the security forces."

"The number of people killed or injured, even according to the government's figures, point to an excessive, even extreme use of force against demonstrators," she said.

Morsi supporters had called for Cairo marches but that call was not heeded, while small protests were staged in coastal Alexandria and southern Beni Sueif.

Meanwhile, attacks against churches and Christian properties that began on Wednesday continued for a second day, with activists saying at least 25 churches had been targeted.

As relatives sought to identify their dead, Brotherhood spokesman Gehad al-Haddad insisted protesters would "remain strong, defiant and resolved."

"We will push forward until we bring down this military coup," he tweeted.

In Cairo, at the Al-Iman mosque, dozens of corpses of protesters clad in white shrouds were lined up before grieving relatives.

At the two protest sites where Morsi loyalists had camped since his July 3 ouster, trucks cleared charred debris.

Meanwhile, Egypt's interior ministry announced new security measures on Thursday, ordering police to use live fire if government buildings came under attacks.

The statement appeared to be a bid to warn against fresh attacks like those that targeted police stations in Sinai and Assuit, and the Giza governorate building in Cairo.

In Sinai, where militants have targeted police and army facilities on an almost daily basis, security officials reported seven soldiers gunned down by men in two cars at a checkpoint near the northern Sinai town of El-Arish.

On Thursday night, the protest group that organised opposition to Morsi's rule, Tamarod, urged Egyptians to take to the streets on Friday.

The group called on "the great people of Egypt to form popular committees on all streets... to reject domestic terrorism and foreign interference."

Despite the bloodshed, Egypt's press welcomed the end of the pro-Morsi demonstrations.

"The nightmare of the Brotherhood is gone," daily Al-Akhbar's front page headline read.

Newspapers carried photos of protesters brandishing weapons and throwing stones, but none from makeshift morgues where dead protesters were lined up in rooms slick with blood.

The killing prompted interim vice president and Nobel laureate Mohamed ElBaradei to resign, saying he was troubled over the loss of life, "particularly as I believe it could have been avoided".

In response to the violence, Egypt's interim government has imposed a nationwide state of emergency and a nightly curfew in 14 provinces.

Despite the condemnation, interim prime minister Hazem al-Beblawi praised the police for their "self-restraint" and said the government remained committed to an army-drafted roadmap calling for elections in 2014.

He justified the use of force saying Morsi loyalists had been sowing chaos, "terrorising citizens, attacking public and private property."

The events are a dramatic turnaround for the Brotherhood, which just over a year ago celebrated Morsi's victory as Egypt's first elected president.

His year in power was marred by political turmoil, deadly clashes and a crippling economic crisis, and turned many against the Islamist movement, with millions taking to the streets on June 30 to call for his removal