Updated

Philippine military officials say 18 combatants have been killed after communist rebels attacked armed tribesmen, who were later reinforced by army troops, in the south of the country in one of the bloodiest attacks of the 45-year Marxist insurgency so far this year.

Army Maj. Gen. Ricardo Visaya said Tuesday that the New People's Army guerrillas attacked Manobo tribesmen in a village of Prosperidad town in Agusan del Sur province, sparking a clash that killed 12 insurgents and four tribesmen.

Visaya says army troops were deployed to reinforce the tribesmen, igniting pockets of fighting that killed a soldier and another rebel.

Regional military commander Lt. Gen. Rainier Cruz says the Maoist rebels were trying to recruit the tribesmen, who refused, resulting in disputes that turned violent.