Five inmates at Kratie provincial prison escaped in the early hours of morning with the aid of a saw.

Four remain on the run, including three killers.

Thim Narin, a provincial coordinator for the rights group Adhoc, which monitors conditions at the prison, say the five inmates used the saw to cut through the wooden walls of their room before escaping over the wall.

The prison break took more than four hours, she said, and added that it was unclear how the inmates obtained the saw. Eight other prisoners who were sharing the room with the escapees did not attempt to flee.

A prison official said that three of the escapees had been convicted of intentional murder. The official, who could not provide details of the case against the men, identified them as: Yen Nara, 26, who was sentenced to 18 years; Thoun Nal, 22, who was sentenced to 15 years; and Saom Soknang, 27, who was sentenced to 10 years. All three remain at large.

Chhoung Seng Hak, the provincial police chief, said Ith Samean – a 35-year-old escapee who was being held in pretrial detention on robbery charges – was re-apprehended, and that police were cooperating with prison officials to track down the other fugitives.

“We won’t allow those prisoners to live outside the prison because they can cause insecurity in society,” he said, and added that the men were likely to face additional charges stemming from their escape.

Jeff Vize, a prison project consultant for the rights group Licadho, said he could not provide information about the frequency of escapes, but expressed concern for the “safety of the prisoners once they are apprehended”.

At the prison in Kratie, he said, prisoners who are considered flight risks are often shackled and denied recreation time, violations of both Cambodian and international law. ADDITIONAL REPORTING BY WILL BAXTER