Survival International has published close-up photographs of the Mashco Piro, an isolated indigenous people in the south-east of Peru.
The Mashco-Piro are known to inhabit the ManĂº National Park, but sightings of them have increased in recent months.
This institution says that many of the native tribes are being forcibly displaced from their homes due to illegal logging in and around the area, and under helicopters flying near oil and gas.
The Mashco-Piro are one of the unknown tribes in the photos and that make up about 100 uncontacted indigenous peoples in the world. And it seems that this tribe killed Nicolas "Shaco" Flores who was a member of a different tribe - he had been trying to make contact with the Mashco-Piro for the last 20 years.
"First contact is always dangerous and often deadly - both for the tribe and those who try to contact them," said Stephan Corry, director of Survival. "The wish of the Indians to leave him alone must be respected."
Survival says the photos are the most detailed sightings of uncontacted Indians ever recorded on camera. The photographer, Diego Cortijo uses a telescope lens to obtain images from about 120 meters away.
Last year, the group wrote to the National Service of Protected Natural Areas of Peru (SERNANP) expressing concern about a video that shows tourists leaving clothes on the banks of rivers to attract the attention of these tribes and photograph them.
Given this, environmental authorities in Peru asked not to come into contact with these isolated Amazonian indigenous after the publication of these photos. "We recommend never trying to come into contact with these (isolated) communities, which strive to stay apart from the outside world," said Mariela Huacchillo, a Sernanp official.
He pointed out that the tourist who tries to come into contact can be a carrier "of fatal viruses" and affect the natives, who are sensitive to contracting diseases that do not exist in those regions.