Egypt's military rulers warned on Sunday of strong measures against anyone inciting sectarian strife, in a bid to ease tensions between Muslims and Christians.

The Supreme Council of the Armed Forces, which took power after president Hosni Mubarak's ouster in February, said it was "exerting all efforts to end sectarian disagreements on the Egyptian street to protect this nation."

Syrian forces arrested more dissidents Sunday in the flashpoint southern town of Daraa and in a Damascus suburb under siege for a week, after two days of fresh bloodshed, activists said.

Anti-regime protesters appealed for new protests to launch a "week of breaking the siege" imposed on Daraa and the Douma suburb, and other towns facing deadly crackdowns.

Russia called for an immediate ceasefire in Libya Sunday and said it had "serious doubts" the West was not targeting Moammar Gadhafi and his family after Tripoli said the leader's son was killed.

"The claims of the coalition members that strikes over Libya do not have the physical destruction of Moammar Gadhafi and members of his family as their goal cause serious doubts," the foreign ministry said in a statement.

Turkey is against foreign intervention in Syria and believes the unrest-hit country should solve its own problems, Anatolia news agency quoted Foreign Minister Ahmet Davutoglu as saying on Sunday.

"We should work to prevent the possibility (of a military intervention in Syria). Foreign intervention in a country like Syria with a heterogeneous social structure might cause unwanted consequences," Davutoglu said.

The Gulf Cooperation Council said on Sunday that a ceremony to finalize a Yemeni pact ending three months of protests has been cancelled after embattled President Ali Abdullah Saleh refused to sign.

"The ceremony that was supposed to be held (Sunday)... will not take place," said the press office of GCC secretary general Abdullatif al-Zayani, after the Gulf-brokered deal between Saleh and the opposition collapsed in tatters.

A NATO air strike killed Moammar Gadhafi's youngest son and three grandchildren but the strongman escaped unhurt, a Libyan spokesman said Sunday, after rebels and NATO spurned an offer for talks to end the crisis.

The house of Seif al-Arab Gadhafi, 29, "was attacked tonight with full power," government spokesman Moussa Ibrahim told a news conference, announcing the deaths in the Saturday evening strikes.

Egypt's Muslim Brotherhood, the country's best organized movement, on Saturday announced the formation of a party to contest up to half of parliament's seats in a September election.

Mohammed Hussein, the group's secretary general, said at a news conference that the movement's consultative council decided at a meeting to adopt a decision to form the new Freedom and Justice Party.

Syrian army troops backed by tanks and three helicopters on Saturday took a prominent mosque that had been controlled by residents in a besieged southern city killing four people, a witness said.

The operation in the town of Daraa came a day after President Bashar Assad unleashed deadly force to crush a months-old revolt, killing at least 65 people, mostly in the border town.

The Libyan opposition Transitional National Council (TNC) on Saturday rejected calls for talks by strongman Moammer Gadhafi, saying he had no role to play in the north African nation's future.

"The time for compromise has passed," said Abdul Hafiz Ghoga, vice-chairman of the transitional council that has shaped itself into a parallel government in the rebel-held eastern city of Benghazi.

Two servicemen and four civilians were killed and another 23 were wounded in south Yemen during a shutdown called by anti-government protesters on Saturday, officials said.

The ministry of defense said an officer and a soldier were killed and two more soldiers were wounded, but gave no further details, Agence France Presse reported.