A Shi'ite fighter gestures during clashes with Islamic State militants in Salahuddin province March 2, 2015.[Photo/Agencies]

The troops, backed by armored vehicles and Iraqi aircraft, have surrounded the town of Dour, some 25 km south of Tikrit, and regained control of many villages north of Samarra, some 120 km north of Baghdad, as well as villages in the Himreen area..

The forces are advancing cautiously as IS militants planted the roads and buildings with bombs. Only on Monday, the explosion experts defused over 150 bombs and eight car bombs.

Large parts of Salahudin province have been under IS control since June 11, a day after bloody clashes broke out between Iraqi security forces and the IS group, which took control of the country's northern city of Mosul and later seized swathes of territories in Nineveh and other predominantly Sunni provinces.