Last week's deadly assault on a U.S. diplomatic mission in the Libyan city of Benghazi was a "terrorist attack," the White House confirmed Thursday.

"It is self-evident that what happened in Benghazi was a terrorist attack," White House spokesman Jay Carney told reporters aboard Air Force One. "Our embassy was attacked violently and the result was four deaths of American officials. That's self-evident."

Tunisia said it was banning all demonstrations on Friday after receiving a tip-off about preparations for violence over cartoons of the Prophet Mohammed published by a French satirical weekly.

"The interior ministry, using its powers under the state of emergency and in order to maintain public order, announces that it is outlawing any form of demonstration anywhere in Tunisian territory on Friday," a ministry statement said on Thursday.

President Bashar Assad has hit out at Saudi Arabia, Turkey and Qatar, accusing them of arming Syrian rebels but insisting they will not win, according to excerpts from an interview to appear in an Egyptian newspaper on Friday.

"They suddenly saw money in their hands after a long period of poverty and think they can buy history and play a regional role," Assad told al-Ahram al-Arabi, which put excerpts from the interview on its website on Thursday.

Shelling by Syrian government forces trying to win back a border post seized by rebels left two Turkish civilians wounded Thursday, a Turkish official told AFP.

They were injured by four fragments of a shell that exploded just on the Syrian side of the border, the official said on condition of anonymity, adding that another unexploded shell was found and the area sealed off while it was detonated.

Israel has dismissed plans to hold a summit on creating a Middle East free of nuclear weapons, saying it was unrealistic to push such an idea given the "current volatile and hostile" climate in the region.

"Any initiative to promote the 2012 conference on the Middle East.. in complete disregard to the present sombre regional realities, is futile," Shaul Horev, head of Israel's Atomic Energy Commission (IAEC) said on Wednesday.

At least 30 civilians were killed and dozens more wounded Thursday in an explosion at a petrol station in northeastern Syria, a human rights group said, with activists saying it was an air strike.

"At least 30 people were killed and 83 were injured, although unconfirmed sources say the number of dead was actually more than 50," the director of the Syrian Observatory for Human Rights, Rami Abdel Rahman, told AFP.

The Palestinian leadership will launch a campaign to upgrade their status at the United Nations this month, seeking support from at least 150 nations, an official said Thursday.

Palestinian negotiator Saeb Erakat said the campaign to upgrade their status from observer entity to that of a non-member observer state would start immediately after Palestinian President Mahmoud Abbas addresses the General Assembly on September 27.

U.S. Secretary of State William Burns flew to Libya on Thursday amid tight security for a ceremony to honor ambassador Chris Stevens and three other Americans who were killed in Benghazi last week.

Burns met Foreign Minister Ashur Ben Khayal on arrival and was also expected to meet Prime Minister Mustafa Abu Shagur and Mohammed al-Megaryef, head of the national assembly.

Diplomats from over 60 nations and the Arab League met in The Hague on Thursday to toughen and improve coordination of sanctions against the regime of Syrian President Bashar Assad.

"We need vigorous implementation," Netherlands Foreign Minister Uri Rosenthal told the opening of the "Friends of Syria" sanctions working group.

Egypt's influential Muslim Brotherhood demanded Thursday that France act against cartoons mocking the Prophet Mohammed in the same way as against the topless pictures of Prince William's wife Catherine.

Its political arm, the Freedom and Justice Party (FJP), called for "firm and rapid measures against the (French) magazine" Charlie Hebdo which printed cartoons mocking the prophet on Wednesday.