German police said Sunday that they had detained a male suspect in his 20s after an attack threat against a night club in Offenburg appeared online.

Police launched a major operation in the southwestern German town on Saturday night, upping security in the town center, the main train station and on the border with France. Security was particularly tight around Offenburg's night clubs and one was cleared out by authorities.

"A dance club in the industrial area was evacuated in the early morning hours for security reasons," police said in a statement. They did not name the club that had been threatened.

Police questioned two male suspects aged between 20 and 25 years old, the statement said. Police searched one of the suspect's apartment but did not find any weapons that could have been related to the attack threat.

One of the men was later released after police ascertained that he was not connected with the online threat.
Police have not yet released further details about the content of the threat or a possible motive.

Germany on high alert

The police operation in Offenburg directly follows another security operation in the German city of Essen. On Saturday, police closed a shopping mall after security services warned of a possible terror attack.

Authorities citied by the German newspaper "Bild" described the threat as a potential multiple suicide bombing.

Two men were arrested in connection with the Essen threat, but they were not being treated as would-be perpetrators.

Germany remains on edge following a series of attacks last year after a rejected asylum seeker from Tunisia drove a semi-truck into a crowded Berlin Christmas market in December, killing 12 people.

rs/jlw (AFP, dpa, Reuters)