In the latest violence, the Local Co-ordination Committees - a network of opponents to President Assad's rule - said 51 civilians were killed on November 14, including 21 in the restive southern province of Deraa and 13 in the city of Homs.

In a separate report, Reuters news agency quotes activists as saying 40 people were killed in the town of Khirbet Ghazaleh near the border with Jordan.

Earlier, King Abdullah became the first leader to openly urge Mr Assad to quit. He said that if he were in Mr Assad's position, he would start talks to ensure an orderly transition.

"I would step down and make sure whoever comes behind me has the ability to change the status quo that we're seeing," King Abdullah stated in an exclusive interview with BBC World News television.

Many Arab leaders have condemned the crackdown on months of protests in Syria. The Arab League voted on November 12 to suspend Syria's membership.

Many Western powers have also urged President Assad to stand down. Both the EU and the US have said he has lost legitimacy but have ruled out military intervention.

On November 14, the European Union tightened its sanctions on Syria. EU foreign ministers meeting in Brussels added 18 Syrian officials to a list of people affected by a travel ban and asset freeze. This brings to 74 the number of President Assad's inner circle who have been blacklisted. The ministers also approved the freezing of loans to Syria from the European Investment Bank.