US knew about mass killings of 1960s

The US government was fully aware of a bloody anti-communist purge by the Indonesian army in the 1960s, with one diplomat at the time describing the bloodletting as "widespread slaughter", recently declassified documents have revealed.

The 39 US embassy documents cover the period from 1964-1968, at the peak of the Cold War, and uncover new details about one of the most tumultuous periods in modern Indonesian history.

Historians say up to 500,000 alleged Indonesian Communist Party (PKI) supporters were killed between October 1965 and March 1966 by soldiers and civilian militias after the army launched a campaign to crush the Indonesian communist party and its leaders following a failed coup.

General Suharto, who put down the coup, blamed the Indonesian Communist Party and rose to power on the back of the bloodshed, going on to lead the world's most populous Muslim nation with an iron fist for three decades.

During his rule, the massacres were presented as necessary to rid the country of communism -- Indonesia had the world's third-biggest communist party after China and the Soviet Union before the killings.

The declassified documents show how US officials across the archipelago knew of the massacres, including the complicity of prominent Muslim civil society groups in the killings.

In one telegram sent from the city of Surabaya on November 26, 1965 the US consul said the number of reports coming in from East Java were an "indication (of) widespread slaughter" adding as many as 15,000 communists may have been murdered in a single massacre.

A month later the same consul said communist prisoners held by the military were being "delivered to civilians for slaughter".

Other victims were "taken out of populous areas before being killed and bodies are buried rather than thrown into river".

A cable the same month from the US consulate in Medan, on the western island of Sumatra, detailed how Muslim preachers described the killings as a religious obligation.