Iraqi security officials said Wednesday that fighters for the Islamic State in Iraq and Syria were advancing on the Haditha Dam, the second-largest in Iraq.

The militants are coming from the north, the northeast and the northwest. The ISIS fighters had already reached the nearby town of Burwana, on the eastern side of Haditha, and government forces were fighting to halt their advance.

Worried that the insurgents would reach the dam on the Euphrates River, about 120 miles northwest of Baghdad, army officers told employees to stay inside and to be prepared to open the dam’s floodgates if ordered to do so, an employee said. […]