BEIRUT (AP) — Activists say that U.S.-led airstrikes have targeted Syrian oil installations held by the militant Islamic State group, killing at least five people.

The Britain-based Syrian Observatory for Human Rights and two local activist collectives say the airstrikes hit refineries and oil fields in the eastern provinces of Deir el-Zour and Hassakeh.

In one incident, the activists said at least five people were killed, including women and children who were likely the wives and children of militants, living near a refinery building.

The Observatory and activists said other airstrikes targeted the Nusra Front, a Syrian al-Qaida affiliate that has fought the Islamic State, and which is one of the most powerful groups fighting to overthrow Syrian President Bashar Assad.

Other strikes targeted Islamic State compounds, checkpoints and military vehicles.