Activists say airstrikes have targeted oil installations and other facilities in territory under the control of Islamic State militants in eastern Syria for a second consecutive day.

The Britain-based Syrian Observatory for Human Rights says the strikes in Deir el-Zour province overnight and early Friday are believed to have been carried out by the U.S.-led coalition against the extremist group.

The Observatory says the strikes hit at least two oil producing areas in Deir el-Zour province overnight. It says air raids also targeted the headquarters of the Islamic State group in the town of Mayadeen early Friday.

Another activist collective, the Local Coordination Committees, also reported four strikes on Mayadeen that it says were conducted by the coalition.