HAMAM AL-ALIL, Iraq (AP) — U.S.-backed Iraqi forces launched a major air-and-ground offensive Sunday to retake western Mosul from Islamic State militants and drive the extremist group from its last major urban bastion in Iraq. Ground units pushed into a belt of villages outside the country's second-largest city, and plumes of smoke rose into the sky early in the morning as U.S.-led coalition jets struck militant positions southwest of Mosul and militarized Iraqi police fired artillery. Iraq declared eastern Mosul "fully liberated" last month after three months of fierce fighting, but the militants have continued to stage attacks there, including two suicide bombings against government forces on Sunday. U.S.