At least 10 people were killed and two wounded when terrorists attacked three vehicles taking workers to an oilfield in Syria’s eastern Deir Ezzor province, the official Sana news agency reported on Friday.
Syrian Oil Minister Bassam Tohme has accused “the US occupation and its elements and terrorist groups” of carrying out the attack to aggravate the suffering of the Syrian people.
The UK-based Syrian Observatory for Human Rights said 12 were killed in the attack near Al Taim oilfield and ISIS militants were responsible.
Oil and gasfields in the region are divided between the Assad regime and US-supported Kurdish militia.
The attack comes days after talks were held in Moscow between oil ministers from Syria, Russia and Turkey.
The meeting helped to thaw relations between Ankara and Damascus after the outbreak of the Syrian civil war 11 years ago raised tensions.
On Thursday, the US-backed Syrian Democratic Forces carried out an operation against ISIS after the group killed SDF fighters during an attack on a prison in Raqqa, north-west of Deir Ezzor province.
Raqqa was the last ISIS stronghold in Syria.
The SDF did not immediately respond to The National's questions about Friday's attack.
The SDF offensive, known as Operation Al Jazeera Thunderbolt, began after the group announced a state of emergency to find ISIS fighters who escaped during the attack.
The SDF also said ISIS militants carried out attacks in Deir Ezzor and Hassakeh, as well as Al Hol camp, which holds more than 60,000 ISIS extremists, fighters' wives and children.
On Thursday, the US Central Command said almost 700 ISIS militants were killed in more than 300 operations carried out this year across Syria and Iraq.
They were conducted in partnership with the SDF and the Iraqi Security Forces.