These pictures were taken on Tuesday, March 25. They show how a tribe of Indians, considered to be "uncontacted" by anthropologists, reacted to a plane flying over their community in the Amazon basin near the Xinane River in Brazil's Acre state.
Uncontacted tribes are peoples who have no peaceful contact with anyone in the mainstream or dominant society. Uncontacted does not mean they have had no contact with anyone else at all.
According to Survival, an organization for tribal peoples' rights, there are about 100 uncontacted tribes in the world.
Leaders of the Ashaninka tribe, which shares territory with this tribe and other uncontacted ones, have asked the government and NGOs for help in controlling what they consider the encroachment of these tribes on their own area, stating that the movement of other tribes is caused by pressure from illegal logging across the border in Peru.
While uncontacted tribes are not "backward" or "Stone Age," they live very differently and choose to reject contact with outsiders.
Uncontacted tribes are likely to have seen airplanes, and usually hide or react with hostility, according to Survival. They make it clear they want to be left alone.