German police closed off an area in Karlsruhe's city center on Friday after several people have been taken hostage at a pharmacy.
Authorities urged the public to stay away from Ettlinger street as special police forces were sent to the area.
"Due to the unclear risk situation, the area is currently cordoned off," the police said on Twitter.
There was no information about the number of suspects involved in the hostage situation, and the police declined to give any details.
Negotiator teams were talking with the hostage taker, public broadcaster SWR reported.
The suspect demanded a ransom of more than € 1 million ($1 million), according to the local daily Stuttgarter Zeitung.
The police did not comment on reports of a ransom demand.
