Twenty-four men fled the notorious Prey Speu detention centre last night after the main gate was left unlocked, an official said today.

Three of the escapees returned voluntarily today, said Mom Chandany, director of the Phnom Penh Department of Social Affairs. The others, whom she identified as mostly drug users and beggars, remained at large.

Prey Speu, known for its severe overcrowding, does not have guards at night, and officials believe the men fled about 8pm. Officials discovered they were missing during a morning check of the room in which they all were housed, Chandany said.

Centre officials then went to inquire with nearby villagers and learned they had seen a group of men whom they didn’t recognise in the village late last night.

Chandany said she had informed Choam Chao II commune police about the escape, but it would be up to authorities to search for and return the detainees. “I don’t have the right to arrest them to bring them to the center again,” she said.

Last month, the centre was holding 500 people, Chandany said. It was built to house less than half that many.

Updates to follow.