Twelve people were killed and dozens wounded when a car bomb exploded at a funeral in Damascus, state TV reported.

Syrian rebels said supporters of President Bashar al Assad had been the target of the attack.

Witnesses said the bomb exploded by Druze cemetery in the Jaramana district of south-east Damascus, hitting the funeral procession of two men killed in bombings a day earlier.

One witness said as many as 150 people had been wounded. Another said she saw charred bodies including children. Syrian TV said 48 people were wounded in the "terrorist car bombing".

The Syrian Observatory for Human Rights, a British-based opposition body which monitors the violence in Syria, said the two men being buried on Tuesday were supporters of Mr Assad.

Meanwhile, Syria's refugee exodus is accelerating and up to 200,000 people could settle in Turkey if the conflict worsens, the United Nations warned yesterday.

Turkey has called for the creation of a safe zone for civilians under foreign protection as fighting in the 17-month-old uprising against Mr Assad intensifies.

Up to 5000 refugees a day have been crossing into Turkey over the past two weeks while the pace of refugees arriving at a camp in northern Jordan has doubled, heralding what could be a much bigger movement there, the UN refugee agency said.

While there is no indication that divided world powers are ready to back a buffer and no-fly zone, as rebels and aid organisations would like, UN Security Council foreign ministers are expected to discuss the idea at a meeting tomorrow.

While Turkey could in theory create a buffer zone itself, it has said it is reluctant to go it alone.

Already hosting more than 80,000 refugees, Turkey has warned it could run out of space if the number goes above 100,000.

"We are already looking at potentially up to 200,000 and are working with the Turkish government to make the necessary plans," a spokeswoman for the UN High Commissioner for Refugees said.

Turkey fears the presence of refugees who are fleeing a conflict with a sectarian dimension could worsen its own tensions and put a strain on resources.

Turkey will open four camps for Syrian refugees by next week, bringing its capacity to 120,000 people, its disaster management agency said, but thousands remain stuck in Syria.

"We will be asking the United Nations to be more active in terms of helping the Syrians on their side of the border," said one Turkish official, who declined to be named. He complained that Turkey had received little help so far.

Relations between Turkey and Syria have deteriorated sharply during the uprising. Syria accuses its neighbour of hosting rebel forces and of backing "terrorist' infiltration, and shot down a Turkish plane in June.