Jakarta, Indonesia - Sumini travelled from her village in Central Java to the capital to ask just one question: "What did I do wrong?"

Indonesian men and women in their late 60s and 70s, clearly tainted by a life of struggle, bravely grabbed their first opportunity to speak out in more than 50 years. Voices breaking with emotion, they spoke clearly and undeniably about mass killings, torture, and unlawful detentions that started in 1965.

Sumini, then 18 years old, had joined a women's organisation linked to the Communist Party because she wanted to empower female farmers. Though she survived, she spent years in prison without any trial and faced discrimination formthe rest of her life.

Dialogue held on 1960s purge

The Indonesian government's decision to open this dark chapter has been lauded by human rights advocates, but it was a long time coming. It took years of pressure from activists and the film by Joshua Oppenheimer who gave the world a gruelling inside look with the Act of Killing, but most of all the courage of thousands of survivors who never stopped fighting for justice.

Their testimonies at a government-sponsored symposium in Jakarta were fragments of a long-hidden truth. They reveal a military that was ordered to go on a murder spree in villages around the country after General Suharto took power. The Communist Party, then the second largest in the world, got the blame for a failed coup and the murder of six generals.

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A process of justice was not enough, Suharto and his troops aided by paramilitary groups, Islamic organisations, and the CIA decided to wipe out anyone remotely linked to the Communists.

Researchers estimate that at least half a million people died. As a result, Indonesia lost a whole generation of intellectuals, farmers, and social activists.

After decades of anti-communist propaganda, the killers still to this day believe they did the right thing. The massacre of 1965 is one of the worst in the 20th century and still divides Indonesians.

The government of President Joko Widodo was the first to break the silence - despite pressure from the military and conservative groups that still insist that talking to victims means giving room to communism. Just last week a discussion organised by survivors before the government symposium was forcefully broken up after threats by a radical group.

But from the start of the Jakarta symposium it was clear that the government was still not prepared to reveal the full truth. A high-ranking general active in 1965 and the government's security minister immediately denied any mass killings took place. Minister Luhut Pandjaitan estimated that fewer than 1,000 people died - a shocking statement for survivors to hear.

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They had travelled from all over the country hoping to be able to hear and tell the truth. But instead of walking out angrily, most just shook their heads and continued their mission of truth-telling.

Indonesia conference to discuss communist massacres

The response showed how immune victims have become after decades of official lies, and how firmly they wanted to use this unique - and maybe only - opportunity to tell their side of the story.Their hopes for justice and a formal government apology are slim. But now the government has opened a Pandora's box.

President Joko will have to come up with a solution acceptable to all those millions of Indonesians whose rights have been denied for more than half a century.

A truth and reconciliation commission, South Africa-style, has been mentioned. But so far the government seems only interested in reconciliation - not so much in the truth.