More than 200 Cambodian staff at the UN-backed Khmer Rouge war crimes tribunal went on strike to demand wages that are several months overdue, an official said.
A majority of the court's Cambodian employees, including interpreters and translators essential to the court's functions, did not come into work on Monday because their wages had not been paid since June, spokesman Neth Pheaktra said.
The national component of the Extraordinary Chambers in the Courts of Cambodia (ECCC) had a shortfall of $3m in its annual budget, Pheaktra said.
"We are very concerned about the possible risk of disruption to the judicial process through the strike by national staff," said UN spokesman Lars Olsen.
"We call on the Royal Government immediately to meet its obligation to pay the national salaries so that the strike can be averted," Olsen said.
The tribunal is currently trying two former Khmer Rouge leaders, former head of state Khieu Samphan, 82, and chief ideologue Nuon Chea, 87, for crimes against humanity, war crimes, genocide and other offenses.
Leng Sary, another defendant, died in March during the trial.