The bomber attacked during a commemoration of Prophet Mohammad's birthday, said Anbar province Deputy Governor Hikmet Khalaf, who was injured in the explosion.

"We were in the middle of a ceremony to celebrate the anniversary of Prophet Mohammad's birthday when a male suicide bomber came to the door of the room and said 'God is Greatest' and blew himself up," Khalaf told Reuters.

A medical source at the local hospital said the blast killed 15 people and wounded 21 others.

The sprawling desert province of Anbar was the heartland of a Sunni Islamist insurgency after the 2003 U.S.-led invasion. Its main cities, Ramadi and Falluja, witnessed some of the fiercest fighting of the war.

Reuters