A militant who once led the Syrian Islamic Front has been killed in an airstrike on a military compound in Idlib province, a state news agency said.
The Syrian Observatory for Human Rights said in a statement that Abdul-Rahman al-Masri, a leader of the armed group known as the Islamic State of Iraq and the Levant (ISIL) in the area, was killed on Sunday.
The Observatory said that al-Mansouri, who was also known as Abu al-Ajami, was part of the Syrian Democratic Forces (SDF) alliance fighting ISIL.
He was killed by US-led coalition forces in the countryside of Idlib province on Saturday, it said.SDF fighters were advancing towards the city of Raqqa, the ISIL stronghold in Syria.
The US and its allies have been targeting ISIL since it declared an Islamic state in 2014.
They are trying to stamp out the group and prevent it from expanding in Syria and Iraq.