Crowds of people travelled to a rural village in north-western Cambodia on Tuesday (local time) after the discovery of what could be a Khmer Rouge mass grave.

Some came to search for the remains of relatives.

Among them was 56-year-old Muoth Sam Khan, who believes eight of his relatives could have been killed and buried at the site, near a former Khmer Rouge prison.

"I have tried not to think about this for 30 years, but when I heard they had found bodies, I had to come," said Muoth Sam Khan, who lives in a nearby village.

An estimated 1.7 million Cambodians - about one in five people in the small Southeast Asian country - died of torture, starvation, medical neglect, hard labor and execution during the Khmer Rouge's 1975-79 rule. The regime ran nearly 200 prisons where inmates were tortured before being killed.

On Saturday, villagers discovered about 20 skulls and the remnants of skeletons - some with legs bound by rope - while excavating the ground in an attempt to sell the land. Historians and researchers say there could be thousands of bodies buried in the area, about 60 kilometres from Siem Reap, the site of Cambodia's famed Angkor temples.

Digging crews are expected to begin work after a Buddhist ceremony planned for later this week, said Chheng Theng, the village chief.

He said hundreds of people have come to the site each day since the bones were unearthed over the weekend.

The Documentation Centre of Cambodia, which collects evidence about Khmer Rouge atrocities, identified the area in 1998 as having several mass graves based on interviews with hundreds of villagers but it was never excavated, said Youk Chhang, its director.

An estimated 35,000 people died at this particular prison, he said. The prison was located between two villages, Do Dontrei and Thkov.

Muoth Sam Khan said eight of his family members were secretly eating some chicken soup one night in 1977 when Khmer Rouge officials stormed in. A few days later all eight were arrested, imprisoned and later killed, he said.

The Khmer Rouge banned private meals as part of its effort to transform the country into a communist agrarian utopia. Common eating areas were set up where people had to eat the meagre meals provided.

"My wife and I don't know if these skulls and bones are my family but we wanted to come and pay our respects," he said.

- AP