At least 11 Islamic State (IS) militants, including a group leader, were killed in air strikes on positions of the extremist militant group in Iraq's western province of Anbar, a security source said on Thursday.

At least six IS militants were killed and 14 others wounded in an air strike by U.S.-led coalition warplanes on an IS position in the IS-held town of Heet, some 160 km west of the Iraqi capital of Baghdad, a provincial security source told Xinhua on condition of anonymity.

In a separate air strike, the international warplanes late on Wednesday night bombarded an IS headquarters in Heet, leaving an IS leader and four of his aides killed and destroying large part of the building, the source said.

Government troops and allied militias have been fighting for months to retake control of key cities and towns in Anbar, Iraq's largest province, from IS militants, who previously seized most of Anbar and tried to advance toward Baghdad.

In Iraq's eastern province of Diyala, an intelligence officer was killed and three soldiers were wounded when a roadside bomb struck their patrol in Mansoriyah area, some 110 km northeast of Baghdad, a provincial security source told Xinhua.

Earlier in the month, a report by the United Nations Assistance Mission for Iraq (UNAMI) estimated a total of 670 Iraqis were killed and 1,290 others wounded in acts of terrorism, violence and armed conflict in February across Iraq.

A previous UNAMI figures estimated more than 22,300 people were killed or injured in armed conflicts in Iraq in 2015.