At least 20 people were killed and 14 more injured on Saturday when a bus crashed on a road between the southwestern Colombian cities of Pasto and Popayan, police said.

Images on Colombian television showed the bus flipped over in the early morning accident, which authorities said may have been caused by a mechanical fault.

Local media said the bus had been close to tumbling down a mountainside, but had come to a halt against a barrier.

(With input from Reuters)