Gunmen sprayed grenades and automatic weapons fire in a market south of Baghdad, killing at least 50 people, mostly Shi'ites. The sectarian attack drew an angry protest from lawmakers who accused Iraqi forces of standing idly by during the rampage. Women and children were among the dead and wounded in the Monday assault in Mahmoudiya, hospital officials said. Late Monday, police said they found 12 bodies in different parts of town - possible victims of reprisal killings. Late Monday, a statement was posted on an Islamist Web site claimed responsibility for the attack in the name of the "Supporters of the Sunni People," which said it staged the assault to avenge the slaying of Sunnis in Baghdad.