Dramatic images of an isolated Brazilian tribe believed never to have had contact with the outside world were published by officials Friday to draw attention to threats posed to their way of life.
The pictures, released by the Brazilian government's National Indian Foundation (FUNAI), showed alarmed natives pointing bows and arrows at the aircraft carrying photographers.
The head of FUNAI's environmental protection unit responsible for the images, Jose Carlos dos Reis Meirelles, told AFP the foundation had known of the existence of the tribe for years -- located in thick rainforest near the Peruvian border -- and many photos had been taken.
"We have been watching this isolated indigenous community for at least 20 years. The idea in revealing the photos was to raise the alarm over the risk threatening them," he said in a telephone interview from western Acre state, where the indigenous group is located.
He explained the tribe had been pushed slowly out of Peruvian territory into Brazil by loggers cutting down their Amazon basin habitat, and that the pace of the illegal deforestation was now accelerating.
"Peruvian authorities recently said this indigenous community doesn't exist. Well, they do exist and they are facing an enormous risk," Meirelles said.
"But they weren't just discovered today. All this region is a cultural mosaic and there are four different identified groups living close to one another," he said.
He said he did not know -- "and didn't care to know" -- what ethnic group the isolated tribe came from.
"All I care about is protecting them, keeping them in their isolation."
The pictures show the tribe's members, their skin painted red and black, in a village of huts with thatched roofs.
The head of FUNAI's Isolated Indians Department, Elias Biggio, told reporters that Meirelles's team had not had any physical contact with the tribe.
Survival International, a British group lobbying on behalf of indigenous people around the world, said on its website there were fears illegal logging in Peru could also endanger the Brazilian tribe by forcing displaced Peruvian tribes into contact with it.
It said there were an estimated 500 isolated indigenous people living on the Brazilian side of the border.
"The world needs to wake up to this, and ensure that their territory is protected in accordance with international law. Otherwise, they will soon be made extinct," Survival International director Stephen Corry said.
His group said there were more than 100 uncontacted indigenous tribes worldwide.