36 Islamic State (IS) militants were killed in clashes and air strikes across Iraq Wednesday, a security source said.

In Iraq's province of Anbar, US-led coalition warplanes pounded a school building used as IS headquarters, leaving 13 militants killed and six others wounded along with four vehicles destroyed, a security source told Xinhua.

Also in Anbar, Iraqi security forces and Sunni tribesmen killed 12 IS militants in clashes in the provincial capital city of Ramadi, according to the source.

In Iraq's province of Diyala, security forces backed by Shiite militia clashed with IS militants and killed four fighters.

Meanwhile, an army helicopter bombed vehicles carrying IS militants, killing seven of them, the source said.

The troops blocked the roads leading to a dam and repositioned themselves around it to prevent IS militants from seizing it.

IS militants want to capture the dam to flood a road linking Diyala to the Shiite holy city Sammara, the source said, adding that the road is usually used by security forces to transport supplies to troops in both areas.

Security in Iraq has drastically deteriorated since June 10, when clashes broke out between Iraqi security forces and Sunni militants. The latter next took control of the city of Mosul and seized territories in Nineveh and other Sunni provinces.