BOGOTA, Colombia

Rare images of the largest uncontacted indigenous tribe in the world were published Wednesday by Survival International, a human rights organization working with indigenous peoples.

More than 50 people who belong to the Mashco Piro tribe have been seen leaving the Peruvian Amazon rainforest in recent weeks in search of food, apparently moving away from the growing presence of logging companies, said the local indigenous organization FENAMAD.

“This is irrefutable evidence that many Mashco Piro live in this area, which the government has not only failed to protect but actually sold off to logging companies,” said FENAMAD’s president, Alfredo Vargas Pio.

The Mashco Piro were photographed at the end of June on the banks of a river near the border with Brazil, Survival International said as it released the photos.

One of the biggest concessions that operates in the area is a logging company called Maderera Canales Tahuamanu SAC, which has built more than 120 miles (193 kilometers) of roads for its logging trucks to extract timber, Survival International said.

The presence of Maderera Canales Tahuamanu workers represents a threat to the survival of the Mashco Piro people, not only due to possible violent clashes with the tribe, but also because loggers could introduce diseases that would be deadly to the indigenous people.

The Mashco Piro, who inhabit an area located between two natural reserves in Madre de Dios in southeast Peru, do not communicate with the outside world. The tribe, estimated to number more than 750, took refuge in remote areas of the jungle to escape exploitation during the "rubber boom" at the beginning of the 19th century. They have since been displaced by the presence of drug traffickers and illegal loggers in their territory.

In 2002, the Peruvian government created the Madre de Dios Territorial Reserve in order to protect the rainforest belonging to the tribe, but it only covers part of the Mashco Piro’s territory. The government of Peru has given concessions of the land for the logging of mahogany and other hardwoods.