Governments challenged by ethnic and nationalist tensions killed, imprisoned and tortured tens of thousands of their citizens in 1989, the human rights group Amnesty International said yesterday in its annual report.

"Around the world, particularly where the tensions erupted into violence, tens of thousands of people became victims of security operations, resulting in disappearances and extrajudicial executions," the London-based group said.

Many actions were triggered by conflicts over the rights of ethnic groups and demands for autonomy or secession, it added.

The report said prisoners were tortured in close to 100 countries. People disappeared or were held in secret detention in more than 20 countries, while government-linked death squads operated in more than 35, it said.

The group listed China, the Soviet Union, the Israeli-occupied West Bank and Gaza Strip, Sudan, Iraq and Guatemala as among the places where ethnic and nationalist conflict led to human rights abuses.

The organization also described a "dramatic" increase in attacks by security forces on human rights activists, lawyers and judges in several Latin American nations.

At the same time, the report noted the release of thousands of so-called prisoners of conscience and greater freedom of expression, movement and association in Eastern Europe in the wake of momentous political changes there.

In the United States, 16 prisoners were executed in 1989, the report said, noting two "disturbing" Supreme Court decisions that people as young as 16 and mentally retarded criminals could be executed.

In the Soviet Union, more than 2,000 people seeking to exercise their human rights were put briefly in prison or psychiatric hospitals, and 20 people were killed when armed security troops broke up peaceful public meetings, the report said. At the end of the year, 60 people prosecuted under criminal law were still imprisoned or forcibly conflined in psychiatric hospitals.

In China, an estimated 1,000 people were killed and thousands more injured in Beijing in June when troops fired into crowds of unarmed pro-democracy protesters. Thousands were arrested, some were severely beaten or tortured and secret executions followed, the report said.

In the Mideast, "Over 260 unarmed Palestinian civilians, including children, were shot dead by Israeli forces, often in circumstances suggesting excessive use of force or deliberate killings," the survey said. "Others died in incidents where tear gas was possibly deliberately misused."

About 25,000 Palestinians were arrested in the Israeli-occupied West Bank and Gaza Strip in connection with the Palestinian uprising and thousands of Palestinians were beaten while in the hands of Israeli forces or were tortured or ill-treated in detention centers, it added.

In Iraq, Amnesty International said, thousands of political prisoners were detained without charge or trial, and torture remained widespread. The Baghdad government also failed to clarify the fate of thousands who disappeared in previous years.

In Africa, Amnesty International reported mass arrests of political prisoners. A coup in Sudan was followed by what could have been the year's largest number of political arrests in sub-Saharan Africa.

In Guatemala, security forces and death squads were reported implicated in hundreds of extrajudicial executions and disappearances. "Death squads continued to rule the streets in many of Brazil's cities" and 18 prisoners died of asphyxiation after they and 33 others were forced into a tiny punishment cell for attempting to escape, the report said.

In El Salvador, Amnesty International documented more than 60 killings alleged to have been carried out by government forces.