A bus carrying about 50 passengers plunged down into a deep ravine in the mountains of southeastern Brazil late Saturday, killing at least 40 people a police official said.

Police Col. Paulo Henrique Hemm told the G1 news portal that at least a dozen other people were injured and taken to nearby hospitals.

Hemm said the cause was still under investigation but that it appeared the driver might have lost control on a curve and the bus then ran off the road and fell into a ravine that is 400 meters (1,300 feet) deep.

He said the accident happened in a mountainous area of Santa Catarina state.