"Multiple injuries in Kreuzberg. We are working in a department store in Hasenheide/Hermannplatz", the message says.
Police confirmed that the attack happened in Hermannplatz.
"We are currently on the spot with many colleagues", Berlin police said on Twitter, adding that U-Bahn station Hermannplatz is currently closed due to the ongoing operation.
The newspaper B.Z. earlier reported that an armoured car was attacked. The police spokeswoman was initially unable to confirm this.