German police said officers were at the scene of a hostage situation in the western German city of Karlsruhe on Friday but that there was no danger to the broader public.
The incident follows Thursday's deadly rampage at a Jehovah's Witnesses hall in Hamburg, putting the country on edge. Gun violence is rare in Germany.
Police in Karlsruhe cordoned off an area in the central part of the city and urged residents to avoid the area.
A large number of officers had been deployed to the site at around 4:30 pm local time, a police spokesperson said, but declined to disclose for tactical reasons how many hostages were taken or how many police were on the ground.
The Stuttgarter Zeitung reported that two people had been taken hostage and that there was a demand for a ransom of a single-digit million euro sum.
The police spokesperson declined to comment on the report.
Earlier Germany's Bild newspaper had reported that the police were in contact with the alleged hostage-taker.
Possible hostages in Germany
Karlsruhe, not far from the French border, is a city of some 300,000 people and home to the Federal Court of Justice, Germany's highest court.
(Reporting by Tom Sims, Riham Alkousaa and Tanja Daube; Editing by Hugh Lawson, Louise Heavens and Raissa Kasolowsky)
