Ammon News - Alarabiya - The Iraqi army launched a major operation Sunday on the crisis-hit city of Ramadi, which had been for weeks controlled by anti-government fighters.

Military spokesman Mohammed al-Askari told state television troops were backed by helicopter cover and imposed a ban on movement within the city.

A police lieutenant colonel in Ramadi city, speaking on condition of anonymity, told Agence France-Presse the operation had begun.

Sunni Muslim tribesmen backed by Iraqi troops had been fighting al-Qaeda-linked militants for control of Iraq's western province of Anbar in a critical test of strength for the Shi'ite-led government of Prime Minister Nuri al-Maliki.

The deployment of tribesmen against the militants was made possible by a deal tribal leaders struck with the Baghdad government to try to counter al-Qaeda.

Parts of Ramadi and Fallujah, west of Baghdad, have been held by militants for days, harkening back to the years after the 2003 U.S.-led invasion when both cities in Anbar province were insurgent strongholds.