Iraqi army and Shiite fighters were involved Saturday in fierce combat against IS militants in Tikrit, North Iraq, while attempting to retake the city, Sky News Arabia reported Sunday. Mayor of Al Alam, Laith Al Jubouri, said the Iraqi forces were facing strong resistance from the terrorist group while attempting to besiege IS inside the towns of Al Alam and Al Dour near Tikrit and cut off their supply routes. The Iraqi army and Shiite militia fighters started a military operation last week to liberate Tikrit from IS, however, their advance is slow as the extremist group plants bombs in the city's surrounding areas. Friday, the Iraqi forces expelled IS militants from Al Baghdadi city, taking control of the city's police station and three bridges on the Euphrates River.