Suspected ISIS attack kills four oil workers in eastern Syria: What to know

At least four people were killed and nine others injured when an explosive device detonated near a bus carrying oil facility guards in eastern Syria on Thursday.

What happened: Syrian media reported that the bus transporting the guards, who work at an oil facility affiliated with the Ministry of Energy, had been struck in the village of Sa'alu, on the road between Deir ez-Zor and al-Mayadeen.

According to a security source who spoke to Reuters, the guards work at al-Taim oil field, in western Deir ez-Zor, territory under the control of the Syrian government.

The Ministry of Energy condemned the incident as a “cowardly terrorist attack.”