WASHINGTON - HUMAN rights groups on Thursday criticised Cambodia's leaders for opposing a new Khmer Rouge trial and urged US Secretary of State Hillary Clinton to show support for the UN-backed court.

Prime Minister Hun Sen said on Wednesday that a second trial due to start early next year of cadres from the genocidal regime would be the last, voicing fear that further prosecutions could plunge the country back into war.

Amnesty International and Human Rights Watch in a joint statement said they 'strongly condemn' statements by Cambodian leaders against the Office of the High Commissioner for Human Rights (OHCHR).

'This attack by the government on the OHCHR Cambodia office should be seen as a direct assault on the UN's human rights mandate, encompassed by the Universal Declaration of Human Rights and the international human rights conventions, many of which Cambodia has ratified,' they said.

The statement said that Mrs Clinton, who visits next week, 'should publicly express support for the OHCHR Cambodia office and the UN's human rights mandate'. UN chief Ban Ki Moon visited Phnom Penh on Thursday and said that the decision whether to pursue more Khmer Rouge cadres would be up to the court.

The court has been investigating whether to open a third case against former Khmer Rouge cadres, but has faced political opposition. Mr Hun Sen was once a mid-level Khmer Rouge member himself before turning against the movement. His government has said that domestic courts can handle any further cases, accusing well-paid foreign lawyers of seeking to try more suspects for their own benefit.

Cambodia criticised on trial