Wicked Little Things(2006)
Submitted by Scott
The children are the ghosts of the children who were buried alive in the Carlton Mine due to an explosion.
When the descendant of Carlton comes back to the mountain to reclaim his land, the children trap him inside of a house and kill him, thus ending their vengeance, but the final shot is of one of the ghosts back in the bedroom playing with her doll and a boy closing the door.