BAGHDAD (AP) — The militants who have overrun large parts of Iraq are now battling ferociously to capture one of the country’s vital resources, water.

Fighters with the Islamic State group launched a three-pronged attack over the weekend in a drive to capture Haditha Dam, in western Iraq, a complex with six power generators located alongside Iraq’s second-largest reservoir. At the same time, they are fighting to capture Iraq’s largest dam, Mosul Dam, in the north of the country.