A memorial at the Tuol Sleng Genocide Museum in Cambodia for more than 12,000 people tortured there when it was a Khmer Rouge prison has been inaugurated.
Buddhist monks chanted prayers at a ceremony at the museum, a former high school that the Khmer Rouge converted into a prison after taking power in 1975.
Deputy prime minister Sok An presided over the ceremony, which was attended by representatives from the United Nations and a UN-backed tribunal trying former Khmer Rouge officials.
He said the memorial, designed like a Buddhist stupa, will "serve as an educational tool for the next generations to remember and prevent the return of such a dark regime".
An estimated 1.7 million people died as a result of the Khmer Rouge's radical policies from 1975 to 1979.
Tuol Sleng was one of a number of torture and execution centers. The tribunal has identified 12,272 victims who passed through its gates, but the actual number is believed to be around 16,000.
Virtually all of them were taken away after the torture to be killed elsewhere and only a handful survived.
The memorial replaces a similar one that disintegrated inside the Tuol Sleng complex and is part of a renovation of the museum that began in 2010.
Mr Sok rejected criticism from human rights groups that the government is interfering in the Khmer Rouge tribunal. "I wish to reiterate that the government will not intervene, will not interfere with the internal affairs of the court," he said.
Prime minister Hun Sen warned recently that adding new defendants could incite former Khmer Rouge members to start a civil war, and that the court's investigations had "almost gone beyond the limit". He has made similar comments on many occasions.
Earlier this month, the tribunal indicted two more suspects - former Khmer Rouge navy chief Meas Muth and former district commander Im Chaem. They were charged with homicide and crimes against humanity, including enslavement and persecution on political and ethnic grounds.
Two of the group's top surviving leaders received life sentences last August for crimes against humanity.