Troops fought a series of gunbattles with separatist Tamil Tiger rebels across Sri Lanka's northern front lines Saturday in which 15 guerrillas and three soldiers were killed, the military said. Army troops destroyed a rebel bunker line in the northern Mannar district, killing nine rebels and wounding 47 others, an officer at the Defense Ministry's media center said on condition of anonymity because he was not authorized to speak on the record. The battle also killed three soldiers and wounded 10 others, he said. Earlier Saturday, a group of Tamil Tigers attacked soldiers guarding a defense line in the Muhamalai area of Jaffna peninsula, which separates government and rebel-held regions in the north, the media center said. Soldiers repelled the attack and the ensuing gunbattle killed six insurgents, it said.