BAGHDAD (Reuters) - U.S. marines engaged in heavy clashes with scores of insurgents near a mosque in western Iraq on Monday, leading to U.S. air strikes which damaged the mosque and left it ablaze, the U.S. military said. A U.S. military spokesman said marines came under fire from around 100 insurgents near the town of Hit, about 107 miles west of Baghdad, and engaged in an hour-long firefight. Air support was called in after the guerrillas took up positions around a mosque in the town. "The mosque is partially damaged and currently on fire," the spokesman said.