Smoke rises after an air strike in Idlib province, Syria on August 24, 2019. (File photo: AFP/VNA)

The airstrike in northwest Syria, which killed senior al-Qaeda leader Abdul Hamid al-Matar, camea few days after a base in southern Syria, used by the US-led coalition fighting the Islamic State group, encountered a drone attack. 

Al Tanf base, set up in 2016 as part of the fight against the IS group,is located near Syria's Tanf border crossing with Iraq and Jordan, but the Syrian government has repeatedly said US troops had no reason to be there.