HINCHINGBROOKE Hospital was closed for three hours on Saturday morning after a man was alleged to have threatened staff.
A spokesman said the Huntingdon hospital was put on lockdown on the advice of police following an incident in the early hours of the morning – the building was closed between 4.30am and 7.30am.
It is believed a man was later arrested after threatening to get a gun.
Staff were said to have been left shaken by the incident, but no one was hurt.
The hospital was operating as normal after re-opening.