In the second day of tribunal "re-enactments," jailed Khmer Rouge cadre Duch on Wednesday toured the infamous prison he once supervised under the regime.

Neighbors stood in silence as a convoy, sirens wailing, carried Duch from his tribunal detention cell to the prison, where as many as 16,000 Cambodians were tortured at the center and later executed.

Many of the dead were buried at the Choeung Ek "killing fields," which Duch and tribunal officials visited Tuesday.

Officials said the tours, called "re-enactments," are part of the standard proceedings at the tribunal, where Duch has been charged with crimes against humanity for his role as chief of the prison.

Tight security prevented media coverage near the prison, in the center of Phnom Penh, as tribunal judges questioned Duch and witnesses at the now-popular tourist site.

"This onsite investigation allowed us to clarify the facts in order to describe the location better," tribunal spokesman Reach Sambath said at the end of a full day. "The accused and witnesses, they moved with judges to different places in this compound, around the site, and each of them gave an explanation to what happened here 30 years ago."

Bun Thoeun, a 70-year-old with a house near Tuol Sleng, said he appreciated the efforts of the tribunal, especially in bringing Duch to the prison.

"But my suffering with Duch is still the same as before," he said. "Since Duch left Tuol Sleng in 1979, he has never returned to see his crime."