Here is what I can remember about the movie:
There are a group of people in a forest camping I think.
In one scene, a girl is slashed several times in the back by the river until she dies and the water is red. The slasher is a human-ish native of the forest.
In another scene, someone is shot with an arrow in the back and he explodes.
In another scene, someone throws a chain towards another, it tightens around the neck of the adversary who falls down and starts bleeding from the mouth as blood spills around him and everyone is leaving.
Does this ring a bell?