Multiple gunshots were fired in central Vienna on Monday evening, according to police, with the location of the incident close to a major synagogue.
Police urged residents to keep away from all public places or public transport.
One attacker was “dead” and another “on the run”, while one police officer had been seriously injured, Austria’s interior ministry said according to news agency APA.
The president of Vienna’s Jewish community Oskar Deutsch said that shots had been fired “in the immediate vicinity” of the Stadttempel synagogue but added that it was currently unknown whether the synagogue itself had been the target of an attack.
He said that the synagogue and office buildings at the same address had been closed at the time of the attack.
“It sounded like firecrackers, then we realised it was shots,” said one eyewitness quoted by public broadcaster ORF.
A shooter had “shot wildly with an automatic weapon” before the police arrived and opened fire, the witness added.