Brazil said Monday it was working hard to stop illegal logging in Amazon rainforest land inhabited by the ethnic Awa people, a group said to be threatened with extinction.

"The Brazilian state must accomplish this task with the utmost determination and we are working hard on it," Maria do Rosario, the minister in charge of human rights, told foreign reporters.

A Brazilian government survey estimates there could be "up to 4,500 invaders, ranchers, loggers and settlers" occupying just one of the four territories inhabited by the Awa, whose total population stands at no more than 450.

Last month, Survival International, a leading advocate for the rights of tribal people worldwide, launched a major campaign spearheaded by Britain's Oscar-winning actor Colin Firth to focus attention on the plight of the Awa, saying they were threatened with "genocide" and "extinction."

According to Survival, there are roughly 360 Awa who have been contacted by outsiders, many of them survivors of massacres, along with another 100 believed to be hiding in the rapidly-shrinking forest.

Do Rosario said Brazil's National Indian Foundation (FUNAI) was conducting surveillance operations on lands traditionally occupied by the Awa.

"There are joint operations with the police to protect the rights of these people," she said.

FUNAI estimates that there are 77 isolated indigenous tribes scattered across the Amazon rainforest. Only 30 such groups have been located.

Indigenous peoples represent less than one percent of Brazil's 192 million people and occupy 12 percent of the national territory, mainly in the Amazon region.