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.

A group of more than 200 heavily armed gunmen attacked a mosque in the Libyan capital and ransacked the tombs of two imams, witnesses said on Monday.

"They arrived shortly after 10:00 pm (2000 GMT, Sunday night), between 200 and 300 of them, in pickups fitted with heavy machine-guns. They took off at about 1:00 am," said Mahmud Rahman, a resident of Tripoli's northeastern Al-Masri district.

A Palestinian was killed in northern Gaza near the border with Israel on Monday, the DFLP group and medics said, in circumstances disputed by the Israeli army.

Adham Abu Selmiya, spokesman for Gaza's emergency services, said a man had been killed by Israeli tank fire but his body was so badly disfigured that medics were not immediately able to identify him.

Syria on Monday warned Turkey against "inflaming" unrest in the country, where more than 3,000 people are estimated to have died in six months of protests against President Bashar Assad.

Buthaina Shaaban, media adviser to the Syrian president, who has repeatedly promised reforms, told reporters in Kuala Lumpur that "armed gangs" were responsible for the violence.

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.

Moscow and Beijing are ready to propose a U.N. resolution on Syria that is more "balanced" than the West's draft that they controversially vetoed last week, Foreign Minister Sergei Lavrov said Monday.

Lavrov said in an interview with Profil magazine that the Moscow-drafted version would condemn violence carried out both by the regime of Bashar Assad and the rebel opposition.

Seventeen fighters of Libya's new regime were killed and 50 wounded in clashes with Moammar Gadhafi loyalists in the desert town of Bani Walid, a military official in Tripoli said on Monday.

"We lost 17 fighters in fierce clashes on Sunday and our forces have withdrawn from the airport where they had taken control," said Salem Gheith, head of the National Transitional Council (NTC) military command center.

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.