A non-governmental group on Tuesday released new pictures of an Indian tribe living in isolation in the Brazilian Amazon and warned that they are threatened by the return of illegal gold miners on their territory.

Survival International, a London-based group lobbying to protect tribal people, said it released new pictures of "an uncontacted Yanomami village in Brazil, 20 years after one of its crucial campaigns created the biggest forested indigenous territory in the world."

"These new pictures emphasize how important the territory is in protecting the Yanomami from goldminers who devastated the tribe in the 1980s," it added in a statement.

Illegal goldmining camps continue to operate just 15 kilometers (nine miles) from uncontacted Yanomami, according to Survival.

Straddling the northern Brazilian states of Amazonas and Roraima, along the border with Venezuela, the Yanomani territory was officially created in 1992.

The Yanomami suffered years of oppression at the hands of gold miners. Violence and disease saw their population fall by 20 percent in just seven years.

With gold prices soaring on the international markets, the gold miners are back in the region.

"Many tribal peoples, including the uncontacted Yanomami, are still threatened by the illegal occupation of their land, so we cant afford to give up the fight," said Survivals head Stephen Corry. "The very existence of uncontacted Yanomami, however, proves that persistent campaigning pays off.

The Yanomami group Hutukara, which has a partnership with Survival, told AFP Tuesday that an amateur Yanomami photographer, Morsamiel Iramari, took the pictures of the isolated tribe in Roraima state in March, after a 10-day search and several overflights with a plane provided by the Indigenous National Foundation (Funai).

"Based on the size of the 'malocas' (collective huts) in the pictures, the group appears to comprise 38 people. The elders say they are 'Waripe' Indians (a sub-group of the Yanomami) who took refuge deep in the forest when the Trans-Amazonian road opened in the 1970's," said Hutukura coordinator Ailton da Silva.

He explained that it was decided to look for this group of isolated Yanomami after other Yanomami reported being hit by arrows when they went hunting in the forest.

"The Yanomami (those who do not live in isolation) would go hunt in the forest and would be hit with arrows," said Ailton da Silva, the Hutukara coordinator. "At first, they thought this was caused by aggressive spirits of the forest."

Da Silva agreed that demarcating indigenous lands was crucial.

"With the creation of the territory, mortality fell and gold miners were kicked out. But they are returning en masse," he bemoaned.

In November, at least 800 police and soldiers were sent to the area to expel the gold miners.

"So far about 50 have been booted out but they are hiding in the forest," added da Salva who urged "cutting off the arm which finances them."

According to Funai, there are 77 isolated Indian tribes in Brazil, scattered in the Amazonian states of Acre, Amazonas, Mato Grosso, Roraima, Rondonia and Maranhao. Only 30 about of the groups have been located.

Survival International believes that there are more than 100 unlocated tribes around the world.