An investigation into a suspected murder case has been launched after four people were found dead at a hospital in the German city of Potsdam, police said  on Thursday.

A 51-year-old woman who works at the hospital is under provisional arrest on suspicion of being the perpetrator.

The motive is unclear and the woman’s identity has not been released.

“A total of four people with fatal injuries and one other seriously injured person were found in various hospital rooms in one ward,’’ police said in a statement.

An initial survey of the scene indicated that all the victims’ injuries could be traced back to “severe external use of force,’’ the statement added.

The exact course of events and the circumstances are still unclear.

First responders arrived at the complex shortly before 9 pm (1900 GMT).

The Berlin newspaper Tagesspiegel earlier reported that those killed were patients.

The Oberlinklinik hospital complex consists of several specialist clinics.

No further information will be released until the victims’ families have been notified.(dpa/NAN)