At least 15 people have been killed in tribal fighting in the mountains of Papua New Guinea. The clashes erupted in Kainantu town in Eastern Highlands province between the Agarabi and Kamano tribes, according to the (BBC). Police said guns and knives were used in the fighting, and that a settlement was burned to the ground. Extra troops have been sent to the area, with police warning further violence could erupt. \"It surprises everybody and I think this is the very first time we\'\'ve seen a massacre or killing of that magnitude in one incident and we did not expect such a thing to occur,\" regional police chief Simon Kauba said.