ISIS militants attacked a convoy of oil tankers guarded by the army in the Syrian desert on Tuesday, killing seven people including two civilians, a war monitor said.
"Five regime forces and two drivers have been killed in the armed attack by ISIS militants" in the east of Hama province, the Syrian Observatory for Human Rights said.
According to AFP, the attackers used machine guns and rocket-propelled grenades, said the Britain-based monitor, which relies on a wide network of sources inside Syria.
In March 2019, ISIS lost the last territory it had held in Syria following a military campaign backed by a US-led coalition, but militants' remnants continue to hide out in the desert and launch deadly attacks.
They have used such hideouts to ambush civilians, Kurdish-led forces, Syrian government troops and pro-Iran fighters, while also mounting attacks in neighbouring Iraq.
Syria's war broke out after President Bashar al-Assad's repression of peaceful anti-government demonstrations in 2011 escalated into a deadly conflict that pulled in foreign powers and global militants.
The conflict has killed more than half a million people and displaced millions.
Last week, ISIS militants claimed responsibility for a rare bombing in Damascus that killed at least six people near the capital's Sayyida Zeinab mausoleum.