BAGHDAD — Iraqi security forces and Shiite militiamen on Sunday broke a six-week siege imposed by the Islamic State extremist group on the northern Shiite Turkmen town of Amirli, as a suicide bombing killed 14 people in Anbar western province, officials said.

Army spokesman Lt. Gen. Qassim al-Moussawi said the operation started at dawn Sunday and the forces entered the town shortly after midday.

Speaking live on state TV, al-Moussawi said the forces suffered “some causalities” and fighting was “still ongoing to clear the surrounding villages.”

Breaking the siege was a “big achievement” he said, for the Iraqi army, elite troops, Kurdish fighters and Shiite militias.

Turkmen lawmaker Fawzi Akram al-Tarzi said they entered the town from two directions and were distributing aid to residents.

About 15,000 Shiite Turkmens were stranded in the farming community, some 105 miles north of Baghdad. Instead of fleeing in the face of the Islamic State group’s rampage across northern Iraq in June, the Shiite Turkmens stayed and fortified their town with trenches and armed positions.

Residents succeeded in fending off the initial attack in June, but Amirli has been surrounded by the militants since mid-July.

Nihad al-Bayati, who had taken up arms with fellow residents to defend the town, said some army units had already entered while the Shiite militiamen were stationed in the outskirts. He said residents had fired into the air to celebrate the arrival of the troops.

“We thank God for this victory over terrorists,” al-Bayati told The Associated Press. “The people of Amirli are very happy to see that their ordeal is over and that the terrorists are being defeated by Iraqi forces. It is a great day in our life.”

State TV started airing patriotic songs following the victory announcement.

On Saturday, the U.S. conducted airstrikes against the Sunni militants and air-dropped humanitarian aid to residents. Aircraft from Australia, France and Britain joined the U.S. in the aid drop, which came after a request from the Iraqi government.