A patient shot a doctor in a university clinic in Steglitz, a southwestern district of the German capital, police said.
The incident happened at around 11 am local time.
The gunman after shooting the doctor killed himself, German newspaper Bild said.
The police have not revealed more details about the attack.
“A patient fired at a doctor in the Benjamin Franklin University Hospital in Steglitz and later committed suicide. The doctor sustained a life-threatening injury and is currently in intensive care,” Berlin police said on Twitter.
— Tonton du Bled (@NextDoorArab) July 26, 2016
A huge posse of police was deployed in front of the hospital and the situation is under control, a witness told Tagesspiegel.
“Heavily-armed officers have secured all entrances. Also, the SEC (special police task force) is at the scene,” the witness told the newspaper.
Employees in the hospital have been “led calmly out of the building,” and police has started investigating the shooting incident.
The attacks happened in a country already on the edge after a series of attacks.
On 18 July, a refugee hacked five passengers on a train, critically injuring three of them.
The ISIS claimed responsibility for the attack.