Kofi Annan, the special U.N.-Arab League envoy to violence-torn Syria, plans to return to Damascus "soon" to further efforts to find a peaceful solution to the crisis, his spokesman said on Friday.

Ahmed Fawzi said no date had been set for Annan's second trip to Syria since he was named special envoy.

The U.N. human rights body said on Friday that a panel of experts will travel to Libya next week to investigate the use of mercenaries in last year's conflict.

The group will hold talks with government officials, civil groups and private military and security companies from May 21 to 25.

Three near-simultaneous bomb blasts at a pet market in east Baghdad killed five people on Friday, officials said, just hours after an attack in the city's southeast left five dead.

The explosions, which occurred at around 7:00 am (04:00 GMT) in the Maamal area, also wounded at least 31 other people, the security and medical officials said.

Iran summoned Bahrain's ambassador in Tehran after his foreign minister told the Islamic republic to stop interfering in his nation's internal affairs, state media reported on Friday.

Foreign Minister Sheikh Khaled bin Ahmed al-Khalifa on Thursday warned Iran to stop meddling over a proposal for Bahrain to form a union with Saudi Arabia.

Syrian authorities have sentenced to death for "treason" an activist who was arrested in April and "brutally tortured," a Syrian human rights group said on Friday.

The death sentence is apparently the first to be reported since an uprising erupted last year against the regime of Syrian President Bashar Assad, which has struck back by trying to crush dissent with deadly force.

Al-Qaida chief Ayman al-Zawahiri urged Saudis to follow Tunisians, Egyptians and Libyans in rising up against their rulers, U.S.-based monitors said Thursday.

"Why don't you rise while you are the sons of the proud and strong tribes that look down upon death in order to lift the humiliation and the oppression?" Zawahiri asked in a video translated by the SITE Intelligence Group.

U.N. leader Ban Ki-moon said Thursday he believes al-Qaida committed a major bomb attack in Damascus that left dozens dead, and that up to 10,000 people have now been killed in Syria.

Ban said President Bashar Assad has still not implemented a peace plan agreed with U.N.-Arab League envoy Kofi Annan.

Three Palestinian prisoners in Israeli jails are refusing food, despite the signing this week of a deal to end a mass prisoner hunger strike, Israeli and Palestinian officials said on Thursday.

An official from the Palestinian Prisoners' Club, which tracks the well-being of the 4,700 Palestinians in Israeli jails, told Agence France Presse that "prisoners Mahmoud Sarsak, Akram Rikhawi and Mohammed Abdel Aziz are still on hunger strike."

Prominent Palestinian writer Salameh Kaileh said on Thursday the Syrian authorities deported him this week to Jordan after three weeks of detention and torture over his anti-regime writings.

"Syrian intelligence raided my house and arrested me on April 23. I was suddenly deported to Jordan on Monday after a three-week detention and torture," Kaileh told Agence France Presse in Amman.

The head of Syria's main opposition bloc, Burhan Ghalioun, announced on Thursday that he is resigning, pending the naming of his successor, just two days after his controversial re-election.

"I will not allow myself to be the candidate of division, I am not attached to a position, so I announce that I will step down after a new candidate has been chosen, either by consensus or through new elections," the Paris-based academic said in a statement.