A total of 224 drug addicts broke out of a rehab center in Chau Tanh in Vietnam’s Tien Giang province on August 11. Reports say the escape may have been a protest against alleged torture in the facility.

On Saturday morning, a dispute between inmates and staff developed into an altercation, the VN Express reported. Soon afterwards, armed with knives and bricks, more than 200 inmates broke out of the center.

A police officer who requested anonymity was quoted by AFP as saying that around half of the escapees have already been caught, and that approximately 100 inmates remain on the run. The officer noted that the facility has experienced several breakouts in recent years.

Escapees who were caught and returned to the center alleged that they had been abused by the staff at the rehab facility. They said they had to work 8 hours a day for “labour therapy” and would be beaten up and forced to kneel for several hours for minor errors, VN express reported.

The Ministry of Labour, Invalids and Social Affairs said it will investigate the complaints. In Vietnam, the law requires addicts to spend up to two years in rehabilitation, but some admit themselves voluntarily, and others are put into rehabilitation centers by their families.