aljazeera | It was one of the bloodiest massacres of the 20th century, well hidden from the outside world - the systematic killing of communists or alleged communists in Indonesia in 1965 and 1966. Researchers estimate that between one and three million people died.
Never before have the executioners spoken out in as much detail as in the recently-released documentary The Act of Killing. In this film, killers in North Sumatra give horrifying accounts of their executions, and even re-enact them.
The killers have always considered themselves heroes because their acts were supported by the government and large parts of society. Many executions were directly committed by the military.
In the years that followed, Indonesians were bombarded with anti-communist propaganda and, until today, most people do not know what really happened.
The film, and a recent report by the Indonesian national human rights commission that called the killings crimes against humanity, have launched a new debate on how the country should deal with this very traumatic past.
Mass graves have yet to be exhumed and victims are yet to see some kind of justice. In many villages, killers and victims' relatives are still living with the awkward reality that 'our neighbour has killed my father'.
Al Jazeera's Step Vaessen talks to former executioners and finds out why so many people - mostly Muslim youths - turned into cold-blooded killers, and why this dark episode in Indonesian history is still very sensitive and alive today.
