The Britain-based Syrian Observatory for Human Rights said that fighters from the Islamic State group seized the al-Tanak oil field early Friday. Another group, the activist collective of Deir el-Zour, also reported the seizure.

The field is in the eastern Syrian province of Deir el-Zour, near Iraq, and it followed the Islamic State group‘s seizure of Syria‘s largest oil field on Thursday. Both oil fields were taken from other rebel groups.