One of the most isolated tribes in the world, the indigenous Peruvian Mashco-Piro tribe, emerged from the Amazon rainforest to supposedly ask a nearby remote community for bananas and machetes.

The Mashco-Piro people are certainly untouched by modern society — they are considered one of 14 or 15 “uncontacted people” by the Peruvian government because their immune systems might not be able to withstand contamination by outsiders. Such uncontacted people, otherwise known as "lost tribes," remain entirely separate from globalized civilization and are often found in dense forest areas in countries like Peru, Vietnam, India, Bolivia, and Brazil. Many of these groups violently oppose contact with outsiders.

Although it is unclear why the Mashco-Piro tribe stepped out of the jungle to approach the Yine people of Monte Salvado, local activists say it might be because urban development has begun to creep into their territory. After their confrontation with the village, the tribe once again retreated into the forest and has not returned.

“It could be they are upset by problems of others taking advantage of resources in their territories and for that reason were demanding objects and food of the population,” Beatriz Huertas, an anthropologist, told the Associated Press.

The local rainforest campaign group, AIDESEP, filmed the tribe crossing a river and carrying bananas as they made contact with the nearby village. The AP wrote that the tribe "may be upset by illegal logging in their territory as well as drug smugglers who pass through. Oil and gas exploration also affects the region."

Their numbers are estimated to be around 100 to 250. In 1894, the tribe retreated into the rainforest after an attack by the private army of Carlos Fitzcarrald, and since then, not many outsiders have seen them. In 2012, a local guide, who had acted as a translator and in-between for the Mashco-Piro and the outside world, was found dead with an arrow in his heart. Because of potential violent attacks on outsiders and the possibility that outsiders may spread diseases to the indigenous people, the government has banned contact.