Syrian opposition activists and state television say government forces have killed a prominent army defector who became a rebel leader.

Rami Abdul-Rahman of the British-based Syrian Observatory for Human Rights and Al-Ikhbariya TV say Yasser al-Abboud was killed during fighting on Monday in the town of Tafas, in the southern province of Daraa.

Al-Abboud was among the first high-ranking Syrian army officials to publicly defect and join the rebels fighting to topple President Bashar Assad's regime. Most military defectors were low-level conscripts, who formed part of the Syrian Free Army.

Al-Abboud once commanded the military council of the FSA and led a rebel brigade in Daraa.

Syria's uprising, now in its third year, began as mostly peaceful protests against Assad but descended into a civil war that has killed 100,000.