NEW DELHI, India (AFP) – Scores of inmates staged a mass breakout from an Indian young offenders detention centre Monday by tying bed sheets together and then scaling down the walls of the three-storey building, police said.

A total of 91 out of 135 inmates, including several convicted murderers, managed to flee the facility in Meerut overnight, although 45 have since been recaptured, the city’s superintendent of police Om Prakash said.

“They removed an iron grill from a window at the back of the building while police were guarding the front,” Prakash told AFP from Meerut in the northern state of Uttar Pradesh.

“This was done so professionally that no one got a whiff,” Prakash added.

Those still on the run include inmates convicted of crimes such as murder, rape, theft and banditry, Prakash added. All are aged under 18.

Police say the break-out was staged sometime between 1:00 am and 3:00 am and the alarm was only raised when officers patrolling near the centre spotted some of the fugitives trying to flag down public transport.

Prakash said that the local authorities were confident that they would recapture the others who had escaped.

“Even earlier inmates from this facility have made several attempts to escape. Once in the past around 40 of them even managed to escape,” Prakash said.

Inmates from the same centre beat a policeman to death in December after he objected to their lewd behaviour with a woman during a court hearing.

There are more than 31,000 inmates in India’s young offender’s institutes, according to the latest official statistics, and there is an ongoing debate about the treatment of juveniles charged with serious crimes like rape, murder and robbery.

Some argue that they need to be treated the same as adult criminals and sent to adult prisons that have a much stricter security, while inmates at juvenile facilities usually sleep in dormitories rather than individual cells.