As many as 25 people were killed and another 13 injured after a passenger bus plunged into a 300-meter-deep ravine in north Peru on Sunday night, authorities said on Monday.

The interprovincial bus was carrying some 50 passengers when it crashed around 10:10 p.m. local time on the highway to Celendin, in Cajamarca department, the head of police in Celendin province, Hugo Uriarte, told local media.

He added that the bus departed with 35 passengers on board but picked up more travelers along the route.

Rescue operations continue but have been complicated by the depth and inaccessibility of the ravine, Uriarte said.