Need a name of movie either Australian or S.African?

I have been trying to find a name of a movie. I wanna say it takes place in Australia but can also be S.Africa. It is about tourist who end up in a national park or state park, and are hunted down by these kids after witnessing a murder. The majority of the movie is spent hiding in the woods. In the end, the lady is finally able to get to a house only to realize the house is of the parents of the kids who were killing everyone, and the father say's he can't let the woman leave.