The evacuation of millions of residents from Phnom Penh after the Khmer Rouge entered the city in April 1975 was decided among the party’s central committee through a series of meetings starting in 1973, former Khmer Rouge Brother Number Two Nuon Chea testified yesterday.

The 80-year-old told judges at the Khmer Rouge tribunal that the evacuation was needed in order to liberate the city and prevent “further loss” of lives under the US-backed Lon Nol regime.

“We needed to evacuate the people to various provinces and cooperatives so that they would have food to eat,” he said.

The initial forced evacuation of the population from urban centres in 1975 is the key subject matter of the first trial in Case 002. Prosecutors described the evacuation of Phnom Penh as the beginning of the “nightmare” of Khmer Rouge rule. Many died along roads outside the city from illness and exhaustion.

During nearly three hours of questioning from Trial Chamber judges, Nuon Chea said that the party was not “100 per cent pure” and was formed in a corrupt and “chaotic” society.

In response to questioning from Judge Silvia Cartwright about his involvement in the alleged plan to forcibly move the urban population, Nuon Chea elaborated on so-called “bad elements” in the cooperatives, focusing on a particular event he witnessed during the regime.

“One day around 4am I was on a car to Siem Reap, I saw flocks of people and I asked: where are you going this early morning? I was told they went to transplant rice and I asked them why it was so early,” Nuon Chea said. “They said that was the order from the superior and I said no, this is not right.”

He then claimed that he was deceived during visits to cooperatives and observed only people who were healthy and “not the skinny ones”.

Trial Chamber Judge Jean-Marc Lavergne later questioned Nuon Chea about an alleged policy to eliminate “bad elements” within the party.

“The revolution is to build the forces, not to smash the forces except in the circumstances where those people, after reeducation and rebuilding on several occasions, could not be reeducated or transformed and those were the vicious people, cruel people who could not be reeducated,” Nuon Chea said.

All three co-accused appeared in the dock yesterday, with 84-year-old Ieng Sary reciting a brief statement reaffirming that he would not be giving any testimony.

Khieu Samphan, 79, said that he would not answer questions until the prosecution presented evidence against him, but read from a lengthy statement in which he said that he did not belong to the party and “did not participate in decision-making processes”.

“Pol Pot considered me as an intellectual who came to live with the CPK,” he said.