Human Rights Watch called on the government of South Africa to bring deposed Ethiopian dictator Mengistu Haile Mariam to justice for massive killings and torture during his rule. Mengistu, who has lived in Zimbabwe since 1991, arrived in South Africa last week for medical treatment.

"Mengistu's forces committed crimes against humanity, and South Africa has the right and the duty under international law to bring him to justice,"said Peter Takirumbudde, executive director of the Africa Division of Human Rights Watch. "So many of Africa's blood-stained dictators have retired into comfortable exile next door. We must stop this cycle of impunity."

Ethiopia has sought Mengistu's extradition to stand trial for organizing the "Red Terror" campaign in which tens of thousands of opponents of his regime are believed to have been slaughtered in the 1970's and 80's. Zimbabwe refused the extradition requests. Mengistu is the leading defendant in trials of 2,000 former officials that began nearly five years ago in Addis Ababa, the Ethiopian capital. Two men were sentenced to death in absentia this month in these trials.

Human Rights Watch, citing concerns about the fairness of the Ethiopian trials, has declined to press for Mengistu's return to Ethiopia. The group suggested, however, that South Africa could try Mengistu before its own courts. The South African constitution incorporates customary international law, which holds that all countries should exercise jurisdiction over crimes against humanity and torture. Alternatively, South Africa could extradite Mengistu to a country which is willing to prosecute the former dictator and guarantee a fair trial, the rights group said.

"There are several options available to the South African government to ensure that Mengistu is finally brought to account for the crimes he committed against the Ethiopian people," said Takirambudde. "South Africa would set a terrible precedent if it just let Mengistu walk away."

From 1974 to 1991, Mengistu's "Dergue" regime was responsible for human rights violations on a massive scale. Tens of thousands of Ethiopians were tortured, murdered or "disappeared." Tens of thousands of people were also killed as a result of humanitarian law violations committed during Ethiopia's many internal armed conflicts. Many others, perhaps more than 100,000, died as a result of forced relocations ordered by the Mengistu regime. These violations are documented in Human Rights Watch's 1991 book-length report Evil Days: 30 Years of War and Famine in Ethiopia.

Human Rights Watch also called on South Africa to enact domestic legislation implementing its obligation under the U.N. torture convention, which South Africa ratified in 1998, to prosecute or extradite accused torturers who enter its territory, as well as to establish its jurisdiction over genocide, crimes against humanity and war crimes committed anywhere in the world.

In the wake of the October 1998 arrest of Gen. Augusto Pinochet, Human Rights Watch has campaigned to bring other former tyrants to justice. Among other human rights criminals now in peaceful exile, the group cited Uganda's Idi Amin currently living in Saudi Arabia, Haiti's Raul Cedras in Panama, Paraguay's Alfredo Stroessner in Brazil and Haiti's death squad leader Emmanuel "Toto" Constant in the United States. In an April 1999 presentation to the United Nations, the group questioned Zimbabwe's refusal to bring Mengistu to justice.