Police armed with sub-machine guns have guarded a Kylie Minogue concert in the German city of Cologne after information about a possible security threat was received, authorities say.
"The concert organiser approached us about a possible threat scenario resulting from social media," a police spokesman told dpa.
"We can't remain idle with something like that."
Some 20 police worked with security and safety staff to monitor the arrival of concert-goers on Tuesday. Police said the concert by the Australian pop star proceeded "completely trouble-free."
Police had received information about a potential disturbance from Belgium, and pictures of a man were placed at the concert venue's entrance. All male attendees had their identities checked upon arriving.
Authorities in Belgium were contacted to make further investigations, the spokesman said.
