Defence attorneys say court is wasting time.

LAWYERS for former prison chief Kaing Guek Eav threatened to walk out of a hearing at Cambodia's war crimes court Monday after accusing prosecutors of again wasting the court's time with irrelevant questions.

Former war correspondent Nayan Chanda was called on by judges to provide a historical account of armed conflict between Cambodia and Vietnam at the time of the Khmer Rouge regime.

But lawyers accused prosecutors of asking questions that had little to do with their client's trial.

"We are here because Duch is charged with crimes pertaining to S-21. I have not heard S-21 mentioned today," co-lawyer Francois Roux said, referring to his client by his revolutionary name.

"If we are to continue at this rate we will be here until next year. If that's what you want, then say so and we'll leave," Roux added.

Judges, however,  rejected the claim, saying it was groundless.

Chanda tells of massacres

Chanda, the former Indochina correspondent for the Far East Economic Review, earlier described to judges the carnage he had witnessed in small Vietnamese border villages that had been the work of the Khmer Rouge.

"I had never seen in my reporting career as many bodies of civilians killed most brutality and just left there.... I wondered what these people had done to deserve such a fate," Chanda said. "I saw a sign in Khmer which was translated for me. It said, ‘This is our land'. ... This was the only explanation I could get," he added.