Members of one of the few remaining indigenous tribes still isolated from the modern world brandished weapons as a helicopter flew over their village in the Amazon.
These remarkable pictures of Envira Indians were taken by Brazilian government officials during several flights over a remote part of Brazil's Acre state
It is extraordinary to think that, in 2008, there remain about a hundred groups of people, scattered over the Earth, who know nothing of our world and we nothing of theirs, save a handful of brief encounters.
