Communist rebels attacked a government militia outpost Saturday in the northern Philippines, provoking a clash in which three guerrillas were killed, police said. The rebels stormed the encampment outside the mountain township of Sallapadan, said Abra provincial police chief Senior Superintendent Alexander Pumecha. About 20 government militiamen resisted the dawn assault, killing three guerrillas, but abandoned the outpost hours later when a larger group of about 100 New People's Army guerrillas attacked, Pumecha was quoted as saying by the Associated Press.