Stab wounds are pretty common. Lots of people have and carry around knives with them, most commonly a machete. Many use the knives for gardening and for cutting down weeds in the bush, but there are times when they also use them for weapons. 
I was called to the ER for a stab wound and was very surprised to find a boy sitting on the table. The story is this kid and his cousin were fighting over the knife. The other kid got a hold of the knife and then used it and stabbed this kid. He spent a day at home, but came in the next day with his mom complaining of pain and some shortness of breath. On exam he has a small knife wound just to the side of his spine. The entry wound itself was pretty small, but it did damage as he had quite a bit of blood in his chest when we put in the chest tube. I really enjoy the process of putting in chest tubes, there is just something about putting my finger in between someone's ribs and getting to feel their lung. It doesn't seem like something that anyone should really be doing, especially not in the ER and especially not to a 10 yo kid, but that is what we had to do. 10 yo are too young, ideally they should be more innocent, they should be out playing with their friends, not fighting with knives.
Pray that kids can be kids and can remain innocent until they get a little older, pray that fighting in PNG would cease among all and that forgiveness would be prevail.