Thousands of confidential documents on human rights violations committed during the military regimes of the 1970s and 1980s have been released by the US Embassy in Argentina.

Human rights groups say up to 30,000 people were killed

The declassified documents sent to Buenos Aires by the US State Department deal with death squads, abductions and disappearances during the so-called dirty war against opponents of the military.

Human rights groups welcomed the move, saying the information would clarify issues and help prosecutors in the cases against officers - including the former military leader, General Leopoldo Galtieri.

He was arrested last month on kidnapping charges, after judges ruled that an amnesty protecting military personnel from prosecution was unconstitutional.

An official investigation concluded that 9,000 people were killed or disappeared during the period of the military governments, although human rights organisations say the figure could be as high as 30,000.

Clues

The Washington-based National Security Archive (NSA), an academic organisation which examined the files, said they include:

• an organisational chart of the death squad unit Battalion 60, with an explicit chain of command leading directly to General Galtieri;

• a specific description of the kidnappings by 601 which are the basis for General Galtieri's arrest warrant;

• a US Embassy cable reporting the Argentine military's embrace of "extra-judicial" tactics, because "the security forces neither trust nor know how to use legal solutions" and because "under present rules 'nobody' is responsible on the record for the executions".

The NSA's Carlos Osorio said the documents also provide clues to the fate of disappeared citizens in Argentina, and "tell the story of a massive and indiscriminate counter-insurgency campaign carried out by the military dictatorship".

He added that the files were a "clear contribution to families seeking information about their missing relatives and to judges seeking to make the military accountable for past abuses".

The documents, which are being made public for the first time, were handed over to Buenos Aires following a pledge made by former US Secretary of State Madeleine Albright in 2000.

They are said to include more than 4,000 pages of cables, memoranda and reports between the US State Department and the US Embassy in Buenos Aires during the years of military rule.