The U.N.-backed tribunal trying former Khmer Rouge leaders opened Wednesday a two-week concluding session of the first "mini-trial" of two leaders charged with being responsible for the deaths of nearly 2 million Cambodians in the late 1970s.
The two-week hearing will hear closing arguments by concerned parties, including the defense, the prosecutors and others.
Originally, four former leaders were charged when the Extraordinary Chambers in the Courts of Cambodia began in 2006, but only Nuon Chea, the head of parliament known as Brother No. 2, and Khieu Samphan, the head of state, remain in the dock.
Both are blamed for the deaths of at least 1.7 million Cambodians from 1975 to 1979.
Of the other two accused, Ieng Sary, former foreign minister, died in March and his wife, Ieng Thirith, former social affairs minister, has been deemed unfit to continue to stand trial.
Both Khieu Samphan and Nuon Chea appeared in court Wednesday.
In consideration of his poor health, Nuon Chea was allowed to retire to another room in the courthouse 20 minutes after the hearing began.
The original case against the four defendants charged with genocide, war crimes and crimes against humanity began in November 2011.
But because the scope of those crimes is massive, the ECCC decided to split the case into two "mini-trials" of the remaining two defendants because of their advanced ages.
The first "mini-trial" is related to the forced evacuation and executions of Lon Nol-regime soldiers between 1970 and 1975 in the northwestern province Pursat.
Lawyers for civil parties seeking redress from the court were given Wednesday to make requests.
From Thursday, prosecutors will be given three days to present their statements and the remainder of the hearing, up until the end of the month, will be for the defense and the defendants.
No date has been set for the second mini-trial.
The lawyers for the civil parties are seeking convictions of the two defendants and reparation and compensation for more than 3,800 victims.