Yim Sot Ronnachit, the 16-year-old son of a fishseller near the famous Cambodian ruins of Angkor Wat, was rounded up with his entire family and several others by soldiers of Democratic Kampuchea, as the new regime that country is called, Men, women and children were tied up at gunpoint, ordered to sit on the ground and bashed in the head with hoes and other instruments until they were dead.

Yim fainted after being hit and was taken for dead. He managed to get away at night, and after a lengthy trek escaped across the board to Thailand last March 1. His father, mother, five brothers from 6 to 20 years of age, and 27 other families from his little town all were killed, without any reason he can imagine except that soldiers distrust former townspeople.

Thach Keo Dara, 20, a former student, was assigned to dig irrigation ditches and separated from his family. He had one day off in every 10, and occasionally met a girlfriend but was not allowed to show any affection or even a sign that they were friends.

The penalty for a minor error, such as being late for work, was a warning. However, the penalty for a third minor infraction, or a more serious initial blunder was being "sent to Angka Leu," a Kampuchean euphemism for evecution.

Thach knew several students and relatives who were "sent to Angka Leu" and heard that his turn might be coming soon, since former students were being killed as they were discovered among the peasantry. He escaped to Thailand last Jan. 7.

The stories of Yim and Thach and 12 other refugees from Cambodia, as recorded in interviews by U.S. embassy officers in Thailand, are a key part of a 300-page document on the situation in Cambodia presented by the State Department last month to the Human Rights Commission of the United Nations.

The 14 Cambodian refugees permitted the use of their real names in the public document. Eight other refugees told their stories but are not identified by name. All the accounts tell a similar history of privation, oppression, tyranny and execution at the hands of the Cambodian regime.

Responding to low-key efforts of the United States and several European countries, a U.N. Human Rights subcommittee on prevention of discrimination and protection of minorities has placed the Cambodian situation on its agenda. A discussion of the subject is expected within a week or two in U.N. meetings at Geneva.

"The U.S. government cannot independently confirm any individual story," said a letter to the U.N. commission from ambassador William vanden Heuvel. "We do believe, however, that the number and consistency of such accounts on the public record underscore the need for further investigation."

Speaking for the United States, vanden Heuvel expressed hope that Kampuchea would agree to a "neutral, responsible" inquiry on its territory. If not, he suggested the Human Rights Commission should collect evidence of its own from the many refugees.