Baghdad, Jun 29 (IANS): At least 51 people were killed on Sunday, most of them Islamic State (IS) terrorists, in clashes, air strikes and gun battles across Iraq, security sources said.

In Anbar province, the army artillery pounded IS positions in Saggara area near the city of Haditha, some 200 km northwest of Baghdad, and left 26 IS terrorists killed, a provincial security source told Xinhua on condition of anonymity.

Meanwhile, the security forces and allied Sunni militias repelled sporadic attacks by IS terrorists on military positions in three villages and Alous area near the IS-held city of Heet, some 160 km west of the capital, killing 15 IS rebels, the source said.

At least 10 people were killed and 19 others wounded in air strikes by Iraqi aircraft on several districts in the IS-seized city of Fallujah, some 50 km west of the Iraqi capital, the source added.

Since March 2, security forces and thousands of allied Shiite and Sunni militias have been involved in Iraq's biggest offensive in order to recapture from IS terrorists the northern part of Salahudin province, including Tikrit and other key towns and villages.

The security situation in Iraq has drastically deteriorated since June last year, when bloody clashes broke out between Iraqi security forces and IS terrorists.

The IS took control of the country's northern city of Mosul and later seized swathes of territories after Iraqi security forces abandoned their posts in Nineveh and other predominantly Sunni provinces.

Iraq has been witnessing some of the worst violence in years. Terrorism and violence have killed at least 12,282 civilians and wounded 23,126 others in 2014, according to a UN report.