Iraqi officials say Islamic State militants have launched an attack against government troops outside the militant-held city of Fallujah, killing at least 17 troops.

The officials, a police officer and an army officer, say three suicide attackers drove explosives-laden military vehicles into government forces' barricades outside Fallujah, west of Baghdad, on Sunday. Clashes broke out afterward. The officials said 15 other troops were wounded.

Both officials spoke on condition of anonymity as they were not authorized to release information.

Backed by Shiite and Sunni paramilitary forces, Iraqi government forces last month launched a wide-scale military operation to dislodge militants from Fallujah and other key cities in Anbar province.