The strategic Iraqi city has been in hands of the Islamic State since June 2014.
Military sources said that the large-scale offensive in Mosul (capital of the northern Ninive province and the country's second city) had already allowed to troops to retake control of various villages surrounding the city and consolidate combat positions.
The operation is backed by Shia volunteers of the People's Mobilization and members of the Sunni tribes, as well as Kurdish and Peshmerga forces.
According to Brigadier General Yahya Rasool, spokesman of the Joint Military Command in Makhmour town, in the east of Mosul, the Iraqi flag already flies, after various villages were retaken by government forces early this morning.
The operation is aimed at progressively destroying the positions of the Islamic State this year.