Earlier reports suggested hostages were taken
An armed police officer who was receiving psychiatric treatment at an Istanbul hospital barricaded himself into a room.
Reports say he also attempted to take his own life.
Turkish media previously reported that an armed man was holding staff hostage at Cerrahpasa Hospital.
Officials have now said no one is being held, but admitted the incident caused panic in the medical facility.
A hospital spokesman told the Dogan news agency all staff have been evacuated from the affected ward.
Police negotiators have been sent to the scene to persuade the officer to give himself up.