The extraordinary images of a startled Amazon tribe 亚马逊部落, their bodies painted red and black, firing arrows at an aircraft circulated the world last week.

The Brazilian government organised a flight packed with photographers to prove that such groups of people still live in isolation （与世）隔绝 in the Amazon rainforest.

Although anthropologists 人类学家 weren't able to name the tribe it's believed that they had travelled a short distance from neighbouring Peru.

Illegal loggers 非法伐木者 have been accused of driving the tribes into Brazilian territory.

Now authorities in Peru's Amazon state of Madre de Dios say they'll stop illegal loggers who travel deep into the forest in search of tropical hardwoods 热带硬木 and are often the first to encounter the tribes.

Apart from the possibility of violent confrontations 暴力冲突, encounters with outsiders are often fatal 致命的 because the isolated people lack the antibodies 抗体 to protect themselves from a common cold 感冒 or the flu 流感.

The Peruvian government has also sent a team to the jungle to determine whether or not the photographed tribe had been displaced 被迫迁移 from Peru by loggers.

It's been reluctant to set aside 划定；保留 new areas of land for uncontacted tribes. Some officials have even denied the existence of such tribes but there are signs of a changing attitude.

In the state oil leasing agency's latest auction of concessions 特许土地的最新拍卖 earlier this year it pointedly avoided areas set aside as indigenous reserves 土著人保留地.

The impact of the latest sighting is forcing Peru to accept that some of mankind's last isolated people live on its territory and it has a duty to protect them.