500 brutal years for native people of the Americas: Five centuries of repression, torture and genocide are chronicled in two human rights reports, writes Caroline Moorehead

DAMIAO MENDES' corpse, lying face down in the mud on a river bank, was found by his sister on 25 June, 1990. He had been shot in the back of the neck. Near him lay the body of his 19-year-old nephew. The two men were Macuxi Indians, living on the border between Roraima, Brazil's most northern state, and French Guiana, on ancestral lands contested by cattle ranchers. Police carried out a brief investigation; no one was brought to trial.

This was nothing unusual. Hundreds of Indians throughout the Americas have been murdered in land disputes in recent years. As the 500th anniversary of Columbus' arrival in America draws near, on 12 October, human rights groups all over the world are marking the occasion with reports on five centuries of repression and attacks on native Americans. 'Contempt' - for every aspect of indigenous life - is the keynote of an Amnesty International report published today.

Before the arrival of Columbus, immense areas of the Americas were ruled over by Indian empires. With colonisation came disease, starvation, battles over land, torture and massacres. In the first 200 years, numbers of native Americans dropped from about 100 million to 4 million; Survival International, in its report, calls this the 'greatest genocide in human history'. Entire peoples vanished - 87 Indian groups in Brazil died out between 1900 and 1957. One irony of next week's festivities will be the total absence of any indigenous people on Hispaniola, the island on which Columbus landed: they disappeared long ago.

The mass killings have slowed down, and the last two centuries have seen a growth in numbers of native Americans to about 35 million. But they have not stopped. Indians may not be dying on the scale of the massacre that took place in El Salvador in 1932, when the army broke a peasant revolt by killing 30,000 people, but the picture is not bright. Throughout the Americas, Indians continue to lose not only their lives but their lands, culture and language. Security forces, 'death squads', civilian vigilantes and drug traffickers all target not only those who speak out for indigenous rights, but ordinary men, women and children who get in their way. Villages have been destroyed and thousands of Indians massacred or tortured in armed conflicts between guerrillas and government forces in El Salvador, Guatemala and Peru.

Fifteen Tzutujil Indians died in December 1990 in Guatemala, when soldiers opened fire on 2,000 unarmed indigenous peasants; three were children. Twenty Paez Indians died on 16 December last year in Colombia, when 60 hooded gunmen attacked the hall where they were meeting. The leader of the San Esteban tribe in Honduras died a week later, shot by a landowner claiming that the land he was farming was no longer his. Amnesty's report is a sickening chronicle of similar stories. Alongside the killings are the 'disappearances', a gruesome term coined in Guatemala in the early 1960s to describe a tactic widely used throughout South America ever since.

Amnesty International and Survival present evidence of systematic ill-treatment and torture of native Americans in custody. North America is not exempt. Mohawk Indians, picked up in September 1990 for protesting against proposals to build a golf course on land in Quebec province in Canada surrounding a Mohawk sacred burial site, were apparently kicked and beaten while in detention. In September last year, the American Indian inmates of Montana State Penitentiary were stripped naked, punched, kicked and made to run the gauntlet of 60 officers swinging batons after a riot in the prison's maximum security unit.

Survival International has drawn up a list of companies which it accuses of seriously damaging tribal people's lands. The main transgressors appear to be Rio Tinto Zinc, the world's biggest mining company, and its many subsidiaries; Newmont Gold (UK); Maxus (USA); Daishowa (Japan); Shell; Exxon and several others, all of which are alleged to have forced people from their lands and polluted rivers and lakes, causing illnesses and killing animals and fish on which the tribal people feed.

The United Nations has designated 1993 as the International Year of Indigenous People.

Human rights violations against the indigenous peoples of the Americas. Amnesty International, 99 Rosebery Avenue, London EC1R 4RE. pounds 7.00 including p&p.

Indians of the Americas. Survival International, 310 Edgware Road, London W2 1DY. pounds 2.50.