Baghdad, March 30 (IANS): At least 30 Islamic State (IS) militants were killed on Sunday in clashes and US-led coalition airstrikes in the Iraqi provinces of Salahudin and Anbar, security sources said.

In Salahudin province, the security forces backed by the US and Iraqi aircraft continued their battles to free the IS-held provincial capital city of Tikrit and made a slight advance in the southern and western districts of Shishin and Dyoum after overnight clashes with the extremist militants.

Sporadic clashes and heavy bombardment on IS positions continued on the other edges of the city, located some 170 km north of Baghdad, Xinhua cited a provincial security source as saying.

A statement from the defence ministry said that the troops killed 26 IS militants in the clashes and destroyed a heavy machine gun on the roof of a building, in addition to blowing up a car bomb.

Late on Wednesday, Iraqi Prime Minister Haider al-Abadi had announced that the Iraqi forces started the final phase to liberate Tikrit and the rest of the northern parts of Salahudin province with the assistance of the international coalition air support.

The battles to free Tikrit from IS militants were stalled for about two weeks as the militants planted thousands of bombs and booby-trapped dozens of buildings and cars.

Since March 2, some 30,000 Iraqi troops and thousands of allied Shia and Sunni militias have been involved in Iraq's biggest offensive to recapture the northern part of Salahudin province, including Tikrit and other key towns and villages, from IS militants.

In Anbar province, the US-led coalition airstrike hit a vehicle said to be booby-trapped with IS militants inside in al-Houze area in the provincial capital city of Ramadi, some 110 km west of Baghdad, destroying the vehicle and killing its occupants, a provincial security source said.

Separately, Iraqi helicopter gunships pounded a weapon warehouse in the militant-seized city of Fallujah, some 50 km west of Baghdad, leaving four militants killed and sparking huge explosions in the warehouse.

The IS group seized parts of Iraq's largest province Anbar and tried to advance toward Baghdad, but several counter attacks by security forces and Shia militias pushed them back.

The security situation in Iraq has drastically deteriorated since June 10 last year, when bloody clashes broke out between Iraqi security forces and the IS.