Iraqi Shiite militia fighters are tightening a noose around the Islamic State of Iraq and Syria (ISIS) group-held city of Falluja west of Baghdad as the first stage of a counter-offensive in the Sunni province of Anbar, likely to determine the course of the conflict in coming months. ISIS seized Anbar's capital Ramadi two months ago, extending its control over the Euphrates river valley west of Baghdad and dealing a major setback to Prime Minister Haider al-Abadi and the U.S.-backed army he entrusted with its defense. While the government initially vowed to swiftly recapture Ramadi, it now appears to have turned instead to Falluja, a city located further downriver and closer to Baghdad, meaning supply lines for a counter-offensive would be less vulnerable. Colonel Ali al-Yasiri, commander of Iraq's 4th armoured regiment, 1st division, which is fighting near Falluja, said plans for a quick offensive to retake Ramadi were shelved in June after commanders concluded that Falluja would be "a dagger pointed at the army in Ramadi" unless it was tackled first. "Our commanders gave us orders one week after losing Ramadi to regroup ... in order to launch a counter offensive to retake Ramadi," he told Reuters. "This decision failed to win support from all military commanders." As the government seeks to claw back territory, Abadi has turned to the mainly Shiite Hashid Shaabi militia fighters who have proven more successful than the army on the ground. In April, the militia recaptured the city of Tikrit, former dictator Saddam Hussein's home town on the Tigris river north of Baghdad. But until the fall of Ramadi in May, the government was reluctant to deploy the Shiite fighters west of Baghdad in the valley of Iraq's other great river, the Euphrates, where Sunni tribes have been hostile to outsiders for generations. The army seems to be taking advantage of the extra capabilities offered by the militia umbrella group, which includes Iranian-backed elements. Yasiri welcomed the Hashid's involvement, saying the army had struggled unsuccessfully for 18 months to contain Sunni insurgents in Anbar. Abadi and the army can also rely on U.S.-led air support, more closely coordinated since U.S. officers moved into a military base less than 10 miles (15 km) from Falluja and started overseeing training of Sunni tribal recruits there. Jets and artillery have been pounding both Falluja and Ramadi, inflicting heavy daily casualties on militants and civilians alike according to medical sources.