The leader of the jihadist rebel force al-Nusra Front was wounded by an army bombing near the Syrian capital on Wednesday, a watchdog said, according to AFP.
Abu Mohammed al-Jawlani was wounded with other members of his group in southern Damascus province, the Syrian Observatory for Human Rights said.
Observatory director Rami Abdel Rahman told AFP that Jawlani had been hit in the foot.
The head of the al-Nusra Front pledged allegiance to Al-Qaeda chief Ayman al-Zawahiri in April, but distanced his group from claims it had merged with al-Qaeda in Iraq.
The announcement followed a message from Zawahiri, urging rebels to fight to establish an Islamic state in Syria, and was received with caution by the mainstream rebel Free Syrian Army.
The pledge of this allegiance generated swift and unprecedented condemnation from Syrian opposition groups.
“We reject the thoughts of al-Qaeda. Syria is a country where moderate Islam prevails,” said Moaz al-Khatib, head of the main opposition group, the Syrian National Coalition, according to Al-Arabiya.
“The bottom line is that al-Qaeda’s ideology doesn’t suit us, and rebels in Syria have to take a clear stance about this,” he added.
Many in the West have raised concerns about arming the rebels, fearing weapons could end up in the hands of radical Islamist groups such as Al-Nusra Front.
Washington has been gradually shifting its policy on providing assistance to the opposition, with Secretary of State John Kerry announcing at the last Friends of Syria meeting in February that the U.S. would start providing direct non-lethal aid to rebel fighters.
Britain and France had been pushing for a European Union arms embargo to be allowed to expire by the end of May. Paris has since appeared more wary about arms supplies since the Al-Qaeda pledge from Al-Nusra.
U.S. Defense Secretary Chuck Hagel acknowledged last week that his government is no longer ruling out arming Syrian rebels, but stressed that no decision has yet been made.