Sunni Muslim tribesmen backed by Iraqi troops fought al Qaeda-linked militants for control of Iraq’s western province of Anbar on Friday in a critical test of strength for the Shiite-led government of Prime Minister Nuri al-Maliki.

Dressed in black and waving al Qaeda flags, hundreds of Islamist insurgents using machine guns and pick-up trucks mounted with anti-aircraft guns battled tribesmen in the streets of the city of Ramadi on Friday, witnesses, security officials and tribal sources said.

The deployment of tribesmen against the militants was made possible by a deal tribal leaders struck with the Baghdad government late on Thursday to try to counter al Qaeda, which has seized government buildings and police stations in Ramadi and the province’s other main city Falluja, tribal leaders told Reuters on Friday.