Rebels bracing for a U.S.-led assault on their Falluja and Ramadi strongholds showed their muscle on Tuesday with strikes on oil pipelines and several attacks on Iraqi security forces. Saboteurs mounted the biggest attacks yet on Iraq's oil infrastructure, blowing up four pipelines in the north and halting most exports via Turkey, oil officials said. Monday night's pipeline attacks also sharply reduced crude supplies to Iraq's biggest refinery at Baiji. In the northern city of Mosul, a suspected car bomb blew up near an Iraqi National Guard patrol, killing two Guards and wounding four, witnesses and survivors said. Roadside blasts and car bombs killed three other members of the security forces and wounded up to a score in the towns of Samarra, Abu Ghraib and Haditha.
