Violence isn't show many times, however, when it's shown and when it is referenced, ( which happens more often than it being shown ). The violence gets very, very brutal.
You can see blood on the ground in one scene.
References to cannibalism.
In one scene, you can hear some screamings and things breaking however, nothing is shown and signs of violence don't seem to exist.
Kids can be seen busted in half in Extremely graphic bloody/gorey detail and can be traumatizing to tons of people and can make most people start crying in fear.