The photos are being used to prove the tribe's existence Image: Gleison Miranda, Funai Enlarge Image

One of South America's few remaining uncontacted indigenous tribes has been spotted and photographed on the border between Brazil and Peru.

The Brazilian government says it took the images to prove the tribe exists and help protect its land.

The pictures, taken from an aeroplane, show red-painted tribe members brandishing bows and arrows.

More than half the world's 100 uncontacted tribes live in Brazil or Peru, Survival International says.

Stephen Corry, the director of the group - which supports tribal people around the world - said such tribes would "soon be made extinct" if their land was not protected.

'Monumental crime'

Survival International says that although this particular group is increasing in number, others in the area are at risk from illegal logging.

What do the pictures tell us? In pictures: Brazil tribe

The photos were taken during several flights over one of the most remote parts of the Amazon rain forest in Brazil's Acre region.

They show tribe members outside thatched huts, surrounded by the dense jungle, pointing bows and arrows up at the camera.

"We did the overflight to show their houses, to show they are there, to show they exist," the group quoted Jose Carlos dos Reis Meirelles Junior, an official in the Brazilian government's Indian affairs department, as saying.

"This is very important because there are some who doubt their existence."

He described the threats to such tribes and their land as "a monumental crime against the natural world" and "further testimony to the complete irrationality with which we, the 'civilised' ones, treat the world".

Malocas, or communal houses, are typically thatched. They often have fires, used for cooking or heating during the night. Smaller structures are used for cooking and other tasks, while larger buildings can be used as sleeping areas, and are usually equipped with hammocks.

The thatched roof does not reach to the ground suggesting that this is an area for communal activities including cooking, socialising or preparing the paste that is used for dyes and body paint.

The woven basket has a strap which would be either worn across the forehead or over the shoulder and would be used during the collection of cotton or other produce.

These men are trying to drive off the plane from which these photographs were taken. They are firing their bows at the aircraft, which had returned to fly over the settlement for a second time, after making a first pass some hours earlier.

The men have large bows made from forest hardwood, which they use to hunt for animals including tapirs, monkeys, deer, wild pigs and other small mammals.

They have also painted themselves with the red dye, urucum, commonly used by tribes in the Amazon. It is made from the seeds of a fruit similar to the horse chestnut. The seeds are ground into a paste to form the dye.

The body paint is most likely a show of aggression, possibly in response to the plane's first flyover.

The black figure may be a woman, although it is impossible to be certain. That this person is not carrying a bow hints in this direction. The black body paint is called genipapo, and is made from fruit. Like the red dye it is likely to be an aggressive display.

The series of buildings have very little space cleared around them, and are set deep into the forest. This suggests that the tribe are keen to keep themselves hidden.

The larger building is most likely used for sleeping quarters, the smaller buildings would be used for food preparation, cooking and other practical tasks.

The surrounding area has signs of cultivation by the tribe, who are probably maintaining gardens of manioc, a type of tuber which would form a large part of their staple diet.