Iran on Thursday said it arrested a number of chief suspects in the assassinations of two of its nuclear scientists in the past two years, and claimed they were linked to Israel.

A statement from the intelligence ministry, published by state media, said "the main elements behind the killings... were arrested and moved to detention" following an investigation of at least 18 months involving surveillance in Iran and abroad.

Syrian opposition groups are to meet in a bid to settle their differences, as the violence in their country threatens to descend into civil war, sources among the groups said Thursday.

Tunisia on Thursday banned protests planned by hardline Islamists demanding a more religious state following the worst unrest since the 2011 uprising that gave birth to the Arab Spring.

The North African country has been rocked by three days of violence that left one dead and dozens wounded after ultra-conservative Salafists took issue with works at an art exhibition they deemed offensive to Islam.

Egypt's top court on Thursday cleared ousted strongman Hosni Mubarak's last premier to run for president and ruled illegal the Islamist-led parliament that sought to bar him, deepening political rifts just two days before the key vote.

The decision handed legislative power back to the generals who took power when Mubarak was overthrown in a popular uprising early last year, a military source said.

Tunisia's Interior Ministry on Thursday banned demonstrations in the face of calls by Islamists for protests to uphold sacred values after Friday prayers, ministry spokesman Khaled Tarrouche told AFP.

"No march has been authorized by the ministry of the interior," Tarrouche said, adding that "the law will be applied against all acts of violence... Some calls for violence are circulating on Facebook."

Libya's supreme court on Thursday struck down as "unconstitutional" a law passed at the start of May that banned glorification of slain leader Moammar Gadhafi.

"In the name of the people, the court has decided on the unconstitutionality of Law No 37," the head of the court's constitutional chamber announced at a brief hearing.

A damning report that slammed Israeli Prime Minister Benjamin Netanyahu's handling of the 2010 flotilla raid has raised fears over how a strike on Iran would be managed, press reports said on Thursday.

The 153-page report by State Comptroller Micha Lindenstrauss dominated the headlines.

Iran on Thursday condemned a string of bombings in Iraq that killed 72 people during a major Shiite commemoration, warning that such "terrorist actions" would spread insecurity in the region.

"Some parties are the main cause of the organized terrorist actions in Iraq ... and they should know that their actions will make the region insecure," a deputy foreign minister, Hossein Amir Abdolahian, told state news agency IRNA.

Bahrain's appeals court on Thursday acquitted nine medics and cut the jail terms of nine others for their role in anti-regime protests last year, in a case which drew widespread criticism from rights groups.

The 20 doctors and nurses in the case worked at Manama's Salmaniya Medical complex, stormed by security forces after a crackdown on a protest encampment at the capital's nearby Pearl Square in March 2011.

Ten people were killed in fighting between Al-Qaida militants and the army for control of the jihadists' stronghold town of Shuqra in southern Yemen's Abyan province, a local official said on Thursday.

"Clashes using machineguns between Al-Qaida militants and the army, backed by local militiamen, left two soldiers dead and 11 wounded," the official in Shuqra told AFP.