Updated

A computer glitch at a Maryland prison made hundreds of jail cell doors simultaneously unlock – but not a single inmate escaped.

In two incidents on Saturday and Tuesday, a computer-controlled system in the Montgomery County Correctional Facility, which allows officers to unlock all cells in case of a fire, malfunctioned, Fox 5 reports.

None of the 650 inmates at the jail ran out of their cells and there was no disturbance, authorities said.

However, police officers in the region were called to surround the building in case of any emergency.

Arthur Wallenstein, the county's director of corrections, told Fox 5 that all the jail cells were later manually locked within an hour of the Saturday incident, but technicians have not been able to figure out the source of the computer glitch.

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