Cambodian premier Hun Sen renewed strong warnings his country could be plunged back into civil war if the UN-backed Khmer Rouge tribunal  tried more suspects from the late 1970s movement.

Hun Sen, himself a former low level commander in the communist regime, made his speech less than a week after war crimes court (the Extraordinary Chambers in the Courts of Cambodia) said it could open investigations against more members of the government which killed up to two million people.

"If you tried (more suspects) without taking national unification and peace into consideration and if war re-occurred, killing between 200,000 and 300,000 people more, who would be responsible for it?" the premier told a ceremony.

"I have achieved this work (peace), I will not allow anybody to destroy it.... The value of peace here is very big," Hun Sen said, lamenting that Cambodia had already been drenched "by blood and tears".
"So anybody, please don't cause more trouble," he added.

The prime minister in a speech in March made similar assertions that further prosecutions at the Khmer Rouge court could destabilise Cambodia, saying that he would prefer the court failed than indict more suspects.

But critics have said there is no risk of renewed fighting since the country's civil war ended in 1998, and have accused the administration of trying to protect former regime members now in government.

The tribunal was created in 2006 to try leading members of the 1975-1979 regime and five former leaders are currently being held on charges of war crimes and crimes against humanity.

The court's long-awaited first trial of Kaing Guek Eav, better known by the alias Duch, is under way and he has accepted responsibility for overseeing the execution of more than 15,000 people at the regime's main prison.

After Duch's trial, the court plans to prosecute former Khmer Rouge ideologue Nuon Chea, head of state Khieu Samphan, foreign minister Ieng Sary and his wife, minister of social affairs Ieng Thirith.