BAGHDAD -- Iraqi troops backed by Shiite militias recaptured key parts of the northern refinery town of Beiji from Islamic State militants on Sunday, a general said.

The commander of the Interior Ministry's Quick Reaction Forces, Brig. Gen. Nassir al-Fartousi, told state TV that the Iraqi flag was raised on a local government building in Beiji and that troops were advancing to other areas, without elaborating.

There was no word on the fate of the contested refinery on the town's outskirts.

Beiji, some 250 kilometres north of Baghdad, fell to the extremist IS group during its blitz across northern Iraq nearly a year ago, but parts of the town and nearby refinery have since been retaken by government forces. The town is strategically significant as it lies on the road to IS-held Mosul, Iraq's second largest city.

Iraqi and Kurdish forces have managed to roll back the IS group in many parts of the country with the help of U.S.-led airstrikes, and recaptured the northern city of Tikrit in April. But last month the IS group captured Ramadi, the provincial capital of the western Anbar province, in the extremists' most significant advance since last year.

The IS group has declared an Islamic caliphate in the territories it controls in Syria and Iraq, and has used oil facilities and smuggling to finance much of its operations.

In neighbouring Syria, the U.S.-led coalition carried out airstrikes against IS positions in the northern town of Souran, which IS captured last week from Syrian rebel groups and members of al-Qaida's affiliate in Syria, the Nusra Front.

The Local Coordination Committees and the Britain-based Syrian Observatory for Human Rights said the airstrikes occurred Saturday night. The Observatory said the airstrikes killed eight IS members, including a local Syrian commander, and wounded 20.

The coalition airstrikes against IS in Souran were the first in the area since the extremist group launched an offensive last month on the northern parts of Aleppo province close to the border with Turkey. IS has captured several villages and towns from the Nusra Front and Syrian rebels.

Since September, the coalition has carried out hundreds of airstrikes against IS in Syria. The coalition has also carried out a handful of airstrikes against the Nusra Front. The U.S. says it has targeted a Nusra Front cell plotting attacks on Western interests.

The main Western-backed opposition group, the Syrian National Coalition, says government warplanes have been attacking rebels in Aleppo province, claiming that the "terrorist interests" of President Bashar Assad's government and the IS group are aligned.

In the northeastern city of Hassakeh, government forces have launched a counteroffensive and regained ground lost to IS last week, state media said. State news agency SANA said government forces have retaken the power station south of Hassakeh as well as the juvenile prison that had been recently seized by the IS group.

Associated Press writer Bassem Mroue contributed to this report from Beirut