Iran is "closer than ever" to the ability to build a nuclear bomb, Israel said on Thursday, as a new U.N. report said Tehran has begun installing next-generation equipment at one of its main nuclear plants.

The International Atomic Energy Agency's report said Iran started installing new and advanced centrifuges at Natanz, which would enable it to speed up the enrichment of uranium.

The Tunisian authorities have arrested suspects in this month's assassination of leading leftist opposition figure Chokri Belaid, the interior minister said.

"The investigation has progressed to the point that suspects have been arrested," Ali Larayedh told reporters, without specifying the number of people detained.

Two Tunisian police were wounded in an exchange of gunfire with presumed Salafists on Thursday in Sidi Bouzid, the cradle of the country's uprising two years ago, a medical source said.

The shooting took place when police after a chase cornered four armed men in a mosque in the center of the town, which is a stronghold of the ultra-conservative Muslim group blamed for unrest around the country.

An Israeli court handed a Palestinian hunger striker eight months on Thursday for violating his parole, but though he has already served most of his sentence, his fate still lies with a military court.

At Jerusalem Magistrates Court, Samer Issawi, 33, was convicted of breaching the terms of his early release from jail in October 2011 by taking his car to be fixed at a garage in the West Bank, his lawyer Andre Rosenthal told Agence France Presse.

Turkey sent jets across its border with Iraq to strike separatists from the outlawed Kurdistan Workers' Party (PKK), a local military source said Thursday.

The jets bombed 12 targets in the Kandil Mountains in the autonomous Kurdistan region of Iraq on Wednesday, the source told Agence France Presse without providing any casualty figures.

Turkey on Thursday accused the international community of failing to honor financial pledges made last month to help Syrian refugees who have fled their war-ravaged country.

International donors at a Kuwait conference on January 30 pledged almost $1 billion (759 million euros) in aid to countries hosting stricken Syrians.

Syria's main opposition group, the National Coalition, denounced as "terrorists" those behind a deadly car bombing in Damascus on Thursday, regardless of who carried it out.

In a statement posted on Facebook, the Coalition stressed that "any acts targeting civilians with murder or human rights violations are criminal acts that must be condemned, regardless of the perpetrator or the justification".

Tunisia was scrambling to find a replacement prime minister on Thursday and pull itself out of a major political crisis two days after Hamadi Jebali quit after failing to form a cabinet of technocrats.

The consultative council of Ennahda was to meet later to choose a successor to Jebali, the ruling Islamist party's number two, who ruled himself out following suggestions that he might be reappointed premier.

Hundreds of Palestinian protesters on Thursday confronted Israeli security forces in the West Bank at a demonstration in solidarity with Palestinian prisoners held by Israel.

Some 2,000 people gathered at the Beitunia military checkpoint on Thursday, hoping to march to a nearby military prison. When the Israeli military prevented them from proceeding, protesters began throwing stones and burning tires, the Associated Press reported.

British Foreign Secretary William Hague on Thursday urged President Bashar Assad's regime to respond positively to an offer of dialogue by Syrian opposition chief Ahmed Moaz al-Khatib.

"There has been a very important offer of negotiation by Khatib of the National Coalition. It is important that that offer is responded to with serious negotiations by the Assad regime," Hague told reporters after holding talks in Beirut with Lebanese President Michel Suleiman.