Gunmen stormed the mayor's office and a police station in Iraq's restive city of Ramadi on Thursday and blew up both buildings, Iraqi police and U.S. Marines said, but there were no apparent casualties. "The explosion destroyed the entire first floor of the building, which caused most of the structure to crumble," the U.S. Marines said of the attack at the mayor's office. "An estimated 50 to 60 windows in the surrounding area were broken as a result of the blast." U.S. forces intervened to secure the site and provided plastic sheeting to help locals patch up their broken windows, the Marines said. Ramadi, some 110 km (70 miles) west of the capital, lies in the Sunni Muslim heartland where anti-American sentiment runs high and U.S. forces come under frequent attack from insurgents who want to expel foreign forces from the country. Last month, U.S.-led forces launched an offensive on the nearby city of Falluja to clear it of foreign Islamist militants and Saddam Hussein loyalists they said were holed up there. --More 2247 Local Time 1947 GMT