(Adds details of attack, Asaad deputy comment)
By Jonathon Burch
ANKARA, March 25 (Reuters) - Colonel Riad al-Asaad, founder of the insurgent Free Syrian Army (FSA), had his leg severed by an explosion in rebel-controlled Syria in an apparent assassination attempt, opposition sources said on Monday.
His wounds were not life-threatening and he was now in hospital in Turkey, a Turkish official said.
Asaad, who set up the FSA in 2011 to fight for the overthrow of President Bashar al-Assad, was one of the first senior officers to defect from the Syrian military.
Syrian opposition sources said Asaad had been hit by a car bomb in the city of al-Mayadin, south of Deir al-Zor in eastern Syria. Al-Mayadin is controlled by several rebel groups, not all of them under the FSA umbrella group.
"The attempt to assassinate Colonel Riad al-Asaad in Deir al-Zor is part of an attempt to assassinate the free leaders of Syria," said Moaz al-Khatib, who resigned on Sunday as the head of the opposition Syrian National Coalition.
Asaad's deputy, Malik al-Kurdi, told the pan-Arab Al Jazeera news channel that he believed the Syrian government was responsible for what he said was an assassination attempt.
A bomb was placed under the car, directly below Asaad's seat, and that he also sustained wounds to his face, Kurdi said.
Asaad was excluded from a Western-backed command of the FSA formed last year. Since his defection he has mostly lived with his family in a camp in Turkey along the Syrian border.
Various Syrian rebel factions fight under the umbrella of the FSA, which has struggled to find regular weapons supplies and build a disciplined command and control structure.
Some prominent Islamist militant groups, including the powerful al Qaeda-linked Nusra Front, are not part of the FSA. (Additional reporting by Oliver Holmes in Beirut and Khaled Oweis in Amman; Editing by Angus MacSwan)