More than 20 people were killed Wednesday and 30 others injured when a bus plunged into a ravine in the Andes, Bolivian police said.

The accident occurred near Challapata in Oruro province, police Maj. Rufo Muñoz told Radio Erbol.

The bus was en route from the southern city of Potosi to La Paz with 55 passengers aboard, the officer said.

Police took 30 injured survivors to a hospital in Oruro city and as many as 25 bodies remain trapped in the wreckage of the bus, Muñoz said, adding that authorities are bringing a crane to the accident site.

Preliminary reports indicate the bus driver was drunk, the major said.

Wednesday's crash came two days after another bus ran off a mountain road in La Paz province and fell 400 meters (1,311 feet), leaving 18 dead and 25 injured. EFE