The attack on a meeting of al-Assad's security chiefs in Damascus on July 18 left four members of his inner circle - including his brother-in-law - injured, emboldening the rebels to take their fight to the capital for the first time.

Maher has not been seen in public since the bombing, while al-Assad himself has restricted his appearances to recorded clips broadcast on TV, leading to speculation about the effectiveness of the leadership as the rebellion grows.

Maher has acquired a fearsome reputation as the commander of the Syrian army's Republican Guard and Fourth Division.

"We heard that he [Maher] lost one of his legs during the explosion, but don't know any more," a diplomat said.

A Gulf source confirmed the report.

The disclosure came as Gulf Arab states told their citizens to leave Lebanon after a Lebanese Shi'ite clan kidnapped more than 20 people in Beirut and initially threatened to seize more Arab nationals.