Lima, Feb 11 : At least 20 people were killed and 33 injured, after a passenger bus plunged into a ravine about 100 metres deep in the northern Peruvian province of Pataz of La Libertad department, local authorities confirmed on Thursday. The Regional Health department reported that the accident occurred at about 14:40 local time on Wednesday in a rural sector between the Andean towns of Tayabamba and Huancaspata, Xinhua news agency reported. According to the report, the interprovincial bus, belonging to the Picaflor company, was heading to Trujillo, capital of La Libertad, from Tayabamba when it skidded off the road. People living in nearby towns arrived at the scene to help the injured passengers, who were taken to health centers in Tayabamba, Huancaspata and Trujillo. Personnel from the National Police and the Public Prosecutor's Office took charge of removing the bodies and initiating an investigation. /IANS