Egypt's military rulers ordered a speedy probe into clashes which killed 25 people, mostly Coptic Christians, as the cabinet held crisis talks amid fears of wider sectarian unrest and Washington urged restraint.

The Supreme Council of the Armed Forces (SCAF) "tasked the government with quickly forming a fact finding committee to determine what happened," in a statement read on state television.

U.S. President Barack Obama is "deeply concerned" about violence in Egypt, the White House said Monday, calling for minority Copts to be protected and stressing the need for timely elections.

White House spokesman Jay Carney issued a statement after clashes in Cairo killed 25 people, mostly Coptic Christians and injured more than 300, sparking fears of widespread sectarian unrest.

The clashes that erupted Sunday between Coptic Christians and Egyptian security forces have raised fears that sectarian and political tensions in the country will increase given that Egypt is passing through a transition period following the ouster of president Hosni Mubarak.

Egypt's ruling military council on Monday ordered a speedy probe into clashes which killed 25 people as the cabinet held crisis talks amid fears of widespread sectarian unrest.

Progressive Socialist Party leader MP Walid Jumblat condemned on Monday the riots that have taken place in Egypt over the weekend, voicing his confidence in the Egyptian security forces’ ability in restoring stability.

He warned in his weekly editorial in the PSP-affiliated al-Anbaa magazine: “It’s necessary to prevent the unrest from developing into sectarian strife.”

Lebanese politicians and clergymen have condemned on Monday the riots between Christians and Muslims in Egypt, with some labeling them as being part of an American agenda to fragment the region, while others viewing them as an impediment to democracy.

Hizbullah voiced in a statement “its great pain and sorrow over the developments in Egypt”, saying they are part of the American agenda bent on “completely fragmenting the region along religious and racial lines.”

Egypt's ruling Supreme Council of the Armed Forces on Monday convened crisis talks and tasked the government with forming a fact finding team to probe clashes that left 24 people dead in Cairo.

The council (SCAF) "tasked the government with quickly forming a fact finding committee to determine what happened and take legal measures against all those proven to have been involved, either directly or by incitement," it said in a statement read on state television.

European Union foreign ministers voiced their "alarm" Monday at sectarian clashes that left 24 dead in Egypt overnight, demanding that freedom of worship be upheld by post-revolution authorities.

"I am very concerned, very alarmed about the clashes in Cairo", said British Foreign Secretary William Hague as he arrived in Luxembourg for talks with his 26 EU counterparts.

Egypt's stock exchange dipped 5% within minutes of opening on Monday, following deadly clashes between protesters and security forces that left 24 people dead, most of them Coptic Christians.

The main EGX-index shed 207.31 points to reach 3,821.40 -- a drop of 5.15% -- a day after the deadliest clashes since a popular uprising ousted President Hosni Mubarak in February.

Israelis were on Monday officially advised to steer clear of the Sinai peninsula in neighboring Egypt during the upcoming Jewish festival of Sukkot, the anti-terror bureau said in a statement.

"In light of the upcoming holiday of Sukkot, the anti-terror bureau reiterates its severe travel warning in respect to the Sinai, and recommends against travelling there," it said, urging all Israelis currently staying to "leave the area immediately" and return to Israel.

The Egyptian government was set for crisis talks on Monday after clashes left 24 people dead, raising fears of widespread sectarian unrest that threatens to widen the cracks in an already fragile transition from Hosni Mubarak's regime.

Prime Minister Essam Sharaf was to convene an emergency cabinet meeting on Monday afternoon, state television reported.