A tourist bus carrying 20 people has plunged off a mountain road in Peru, killing four people and injuring 16 others.

Officials said the bus was carrying 17 international visitors plus two Peruvians and the driver.

The bus was returning from a trip to Machu Picchu, Peru’s iconic attraction in the Andes Mountains, when the driver appears to have lost control in the fog.

It fell more than 300 feet into a chasm.

The four dead include one Peruvian and three Colombians. The injured tourists are from several countries including France, Greece, Israel, Canada, the Netherlands and Argentina. They were taken to hospitals in Cusco, the nearest major city, where at least one of the injured is in intensive care.

The National Police of Peru is reportedly investigating the crash.