Baghdad, Sep 22 (IANS) Fierce clashes continued between the Iraqi security forces and the Islamic State (IS) Sunni extremist group across the crisis-torn country Sunday, security sources said.

In western Anbar province, the Iraqi forces launched an offensive aimed at breaking the siege of more than 400 officers and soldiers, who were surrounded by IS militants for six days in Saqlawiyah, 50 km west of Baghdad, Xinhua quoted a provincial police source as saying.

The troops retook control of part of Saqlawiyah as they advanced from two directions towards the besieged soldiers and managed to break the siege, but the fierce battles were still underway, the source said.

Dozens of insurgent militants have been killed and wounded in the clashes, the source said.

He added that in one incident, a warplane bombed IS position in Sicher area, leaving 13 militants killed, including their local leader.

In Salahudin province, heavy airstrikes continued against IS positions in and near Tikrit, 170 km north of Baghdad, a provincial security source said.

The airstrikes, which some believed to be carried out by US warplanes, pounded the militants' positions in central Tikrit and in the northern edges of the city.

The US forces apparently were rebuilding a forward operating base to control the combat operations with IS in central and northern Iraq, the source said, adding that such move would be part of cooperation between the Iraqi government and world efforts to fight the extremist IS militants.

In the country's eastern province of Diyala, heavy clashes broke out between security forces backed by Shia militias and IS militants in several villages near Maqdadiyah, leaving four security members dead and 14 others wounded, including six Shia militiamen, a provincial security source said.

Sadiq al-Husseini, head of the security committee of the provincial council, said at least 25 IS militants have been killed in the clashes and several of their vehicles were destroyed in the battles.

The security situation in Iraq began to deteriorate drastically after June 10, when bloody clashes broke out between Iraqi security forces and hundreds of IS militants. The militants have taken control of the country's northern city of Mosul and seized swathes of territories after the Iraqi security forces abandoned their posts in Nineveh and other Sunni-predominant provinces.