U.S. forces have launched an offensive against insurgents in western Iraq near the Syrian border, and about 75 militants were killed in the first 24 hours, the Associated Press quoted military as saying on Monday. It said the offensive, being conducted with U.S. air support in a desert area of Anbar province north of the Euphrates River, was targeting a sanctuary for foreign insurgents and a smuggling route. The brief U.S. statement didn't say when the offensive by Marines, sailors and soldiers had begun, how many were included, or whether there had been any American casualties. The Chicago Tribune reported Monday that more than 1,000 U.S. troops supported by fighter jets and helicopter gunships had attacked villages in and around Obeidi, a city near the Euphrates River in western Iraq not far from the Syrian border, on Sunday.