Baghdad, Aug 19 (IANS): Iraqi forces Tuesday launched a major offensive to recapture the militant-seized city of Tikrit, the capital of the Sunni-dominant province of Salahudin, a security official said.

Dozens of military vehicles, backed by tanks, armoured vehicles and helicopters advanced from three routes toward the city of Tikrit, some 170 km north of Baghdad, the official told Xinhua.

One of the routes was from the small town of Uoja, some 12 km south of Tikrit, which was the scene of fierce clashes in the past few days between the security forces backed by Shia militias and anti-government Sunni militant groups, including those who are linked to the Islamic State (IS).

The troops also advanced toward the city from Jillam area southwest of Tikrit and Deum area northwest of the city, the official added.

Fierce clashes are under way on the three routes with the militants who planted landmines and bombs on the roads.

Tikrit, hometown of former president Saddam Hussein, has been under the control of IS Sunni extremist group, previously known as Islamic State of Iraq and Greater Syria (ISIS), since June 11.

The seizure of the city was part of the June 10 drastic security deterioration in the country, when bloody clashes broke out between Iraqi security forces and Sunni militants who took control of the country's northern city of Mosul and later seized swathes of territories in Nineveh and other predominantly Sunni provinces.