The trial of three former Khmer Rouge leaders has begun Monday, more than 30 years after they ruled Cambodia, where they face charges of war crimes, crimes against humanity and genocide.

In a packed courthouse the prosecution’s opening statements were read out, accusing the three former leaders of causing the death of more than 1.8 million people during the late 1970s.

Prosecutor Chea Leang gave a detailed account of the massacres, causing some of those in the courthouse to shed tears. She told the UN-backed tribunal,

"The forced evacuations of Cambodian cities, the enslavement of millions of people in forced labour camps, the smashing of hundreds of thousands of lives in notorious security centres and the killing fields, and the extermination of minorities, the countless deaths from disease, abuse and starvation – these crimes ordered and orchestrated by the accused were among the worst horrors inflicted on any nation in modern history."

Court spokesman Lars Olsen hailed the trial, saying that "many people never thought it would happen."

International co-prosecutor Andre Cayley also told reporters that the opening of this case was a milestone achievement.

“I also think it is important in the interests of international justice generally because it’s certainly part of the fight against impunity.

We are looking at crimes that are 30 years old.

I’m quite certain that at the time the leaders of the Khmer Rouge never believed they would be held to account for what happened, and here we actually have the most senior living members of the Khmer Rouge who will be standing trial."

Cayley went on to say that whilst the accused may not have personally killed anyone, they all played a vital role in ensuring the massacres took place.

He stated,

“None of the accused here ever soiled his hands with blood, but all set in motion a series of policies which unleashed an ocean of blood.”

The point was reinforced by Leang who told the court that the killings were “organised and systematic” with a “high level of integration” and the defendants were aware of what was happening at all times.

“These were not unauthorized, random crimes. The Khmer Rouge leadership, which included the three defendants, was kept constantly informed by periodic reports... (and) often directly involved in purges.”

“The accused participated in the giving of these orders or were fully aware of the crimes. They failed to act in their capacity as superiors to prevent the crimes or to punish the perpetrators.”

The three defendants are Nuon Chea, 85 and "Brother Number Two" to Pol Pot; Khieu Samphan, 80, who served as president; and 86-year-old Ieng Sary was the Khmer Rouge’s foreign minister.

Another of the accused, the former social affairs minister Leng Thirith was suffering from dementia and declared unfit for trial.

Many of those who attended the trial lost relatives throughout the regimes brutal rule.

Chum Noeu, 62, who lost 13 relatives said,

"We want justice so that the dead can finally close their eyes. What is the truth behind all of torture and killings? What happened?"

Meas Sery, 51, said he travelled to Monday's hearing from his home province, just to see for himself the faces of the defendants. He has lost four siblings under the Khmer Rouge regime.

"Even though there is no verdict be announced yet, I am happy to see these three leaders brought to the court.

I believe that justice will come and I will receive it soon."

See our earlier post: Khmer Rouge prosecutor confident of ‘strong’ case (Nov 2011)