The official, a member of the Anbar police command, said security forces backed by Shiite militias and local tribes had regained control of Tash and Hamira south of Ramadi, cutting off ISIS supply lines in the area.

Meanwhile, a pro-government Shiite militia, known as the Popular Mobilization, announced it had advanced into the area of Nabai near Ramadi, forcing the extremists to retreat.

"Daesh elements escaped once the ... Mobilization fighters entered into Nabai," Hassan al-Sari, a field commander in the militia, told Iraq's Alsumaria news.

He added that the major militia force had pushed around 20 kilometres deeper into the area.

The Shiite militia played a substantial role in retaking the northern city of Tikrit two months ago.

"The role of the Mobilization is to defend Iraq," spokesman for the militia, Karim al-Nouri, told DPA.

"If it hadn't been for the Mobilization, Daesh could have entered Baghdad and deposed the government and parliament."

Al-Nouri said his force takes orders from the premier.