Four tourists were killed and 16 injured after visiting Peru's world-famous Machu Picchu site when the minibus they were traveling in crashed into a ravine, authorities said Monday.

Three of the dead tourists were Colombians and the other Peruvian, said the tourism and foreign business ministry.

Amongst the injured were four French people, two Greeks, two Israelis, two Canadians, two Argentines, two Peruvians, a Dutch person and a Spaniard.

The minibus fell down "a ravine of a little more than 100 meters," said Roberto Sanchez, the tourism and foreign business minister.

The accident happened Sunday night around 100 kilometers from the city of Cusco, the former Incan empire capital which is the main departure point for many people visiting the Machu Picchu World Heritage site.

"There was fog where the accident happened," added Sanchez, who said the tourists were heading back from Machu Picchu, which is set in the Andes mountains.

He said some of the injured tourists would soon be transferred to the Peruvian capital Lima by an Air Force plane.

Road accidents are common in Peru where speeding, poor road surfaces, a lack of road signs and little control by authorities exacerbate the problem.

Three weeks ago, 16 people died when another minibus crashed into a ravine in the central Junin province.

Some 5,000 tourists daily visit the Machu Picchu citadel, which was built in the 15th century by the Inca emperor Pachacutec.