A bus carrying students on a trip to Bolivia has overturned in a curvy mountain road in northern Chile, leaving 9 teenage girls dead and 21 injured.

Deputy Interior Minister Felipe Harboe said Friday that the cause of the wreck in northern Chile is being investigated.

The bus was carrying students on a trip to neighboring Bolivia when it overturned at a curvy stretch of the road along deep ravines.

Police say 10 of the injured students are in serious condition.

The students are from the Cumbres private school in Santiago.