By Tom Phillips in Roraima state, Brazil.
February 19, 2008

One by one they emerge from the thick, green tangle of rainforest; tiny brown specks, flecked with red paint, fluorescent green parrot feathers and with tiny bamboo sticks jutting out from below their mouths.

They pause, suspiciously eyeing their visitors, before continuing their descent down the steep ravine, across a small creek and into the jungle clearing. Up close the specks form a queue of men, women, children and even emaciated dogs all painted in identical tribal colours and nearly all with white feathers pasted across their foreheads.

These are the Yanomami; a group of just under 30,000 indigenous people who live in one of the most remote and mysterious regions of the Amazon, a Portugal-sized area of almost pristine jungle, straddling the border between Brazil and Venezuela. For thousands of years the Yanomami have inhabited the region living in an almost identical way, hunters and gatherers, bound by age-old traditions and isolated from the modern world, deep in the world's largest tropical rainforest.

But for how long? In the 1980s, some 40,000 illegal wildcat miners poured into the Yanomami's ancestral lands in search of gold. The tribe was decimated by illnesses brought by the white man and by a violent physical assault aimed at expelling them from their territory. Many died from the flu or a malaria epidemic that swept the region. Others were simply shot. Human rights groups labelled what followed a "genocide". According to some sources, before the government expelled the miners in 1992, up to 20% of the Yanomami people died in just seven years.

Now the Indians fear history may be about to repeat itself. At the end of last year, the indigenous rights NGO Survival International reported that hundreds of illegal miners - known in Brazil as garimpeiros - were again flocking into Yanomami lands. Activists fear that the miners are likely to unleash a new wave of destruction in the region; bringing violence, alcoholism, disease and prostitution to the region's virtually untouched indigenous villages.

In October 2007 the world-famous Yanomami leader Davi Yanomami travelled to London to make a personal plea to the prime minister, Gordon Brown.

"My Yanomami people are suffering and our future is threatened," he wrote in a letter to the British leader. "Our land is being invaded by gold miners who pollute the rivers and bring in diseases.

"Yanomami," he concluded, "are starting to die."

For Yanomami Indians such as 25-year-old Graciano Yanomami (many of Brazil's indigenous people use their tribal name as their surname) the consequences of such an invasion are as predictable as they are terrifying. In the late 1980s, Graciano saw his tribe almost destroyed by the arrival of the wildcat miners, who came carrying both shotguns and illnesses to which his people had no natural immunity.

"When the gold miners came, my mother died. My father died. My sister died," he says matter-of-factly, sitting in a small jungle clearing deep in the Amazonian state of Roraima, a two-hour flight from its state capital Boa Vista.