An Indian tribe that has had no formal contact with Western civilization has been located in a remote Amazon region, federal authorities said Friday.
The Metyktire tribe, with about 87 members, was found last week in an area that is difficult to reach because of thick jungle and a lack of nearby rivers some 2,000 kilometers (1,200 miles) northwest of Rio de Janeiro, said Mario Moura, a spokesman for the Federal Indian Bureau, or Funai.
The tribe is a subgroup of the Kayapo tribe, and lives on its 4.9-million-hectare (12.1-million-acre) Menkregnoti Indian reservation, Moura said.
The Kayapo had no significant contact with the Metyktire until two tribe members inexplicably appeared at a Kayapo village last week, he said.
"We don't know why they decided to make contact now ... only time will tell. This is a very slow process," Moura said.
Uncontacted tribes are usually discovered when loggers and ranchers encroach on their territories.
Patrick Cunningham of the London-based Indigenous People's Cultural Support Trust, which is involved in an unrelated expedition in the region, said in an e-mail that the tribe speaks an archaic version of the Kayapo language and goes naked.
Like many less-assimilated members of the Kayapo, the men wear penis sheaths and several have plates in their lower lips, he said. The women shave the tops of their heads.
Cunningham, who has not met the tribe, said the Kayapo believe it is was formed by a group of families who fled deeper into the forest when the pioneering Indian defender Orlando Villas Boas appeared in the area in the 1950s.
Megaron Txcucarramae, a Kayapo Indian and Funai representative in the region, met with the newly found group in Kremoro village and banned all but a medical team from entering or leaving, fearing the tribe could be more vulnerable to diseases than the Kayapo, Cunningham said.
Miriam Ross, a campaigner with the indigenous rights group Survival International, estimates there are more than 100 uncontacted tribes across the world.
"This proves that often we just don't know whether these people are there or not," Ross said by telephone from London.
About 700,000 Indians live in Brazil, mostly in the Amazon region. Some 400,000 live on reservations where they try to maintain their traditional culture, language and lifestyle.
Indians were pushed deeper into the jungle by settlers and it is relatively uncommon for the Indian Bureau to come across previously uncontacted native groups.
The bureau said that it has learned from other Indians of a few uncontacted tribes in the western Amazon state, where the region's jungle is thickest.
Moura said anthropologists no longer attempt to contact those groups, but instead demarcate the land and wait for them to make contact.