Several gunmen attacked six locations in central Vienna on Monday starting outside the main synagogue, killing three people and injuring 13-15 in what Austria called a "repulsive terror attack".
Witnesses described the men firing into crowds in bars with automatic rifles, as many people took advantage of the last evening before a nationwide curfew was introduced because of COVID-19. Police shot and killed one assailant.
Police sealed off much of the historic centre of Vienna, urging the public to shelter in place. Many sought refuge in bars and hotels, while public transport throughout the old town was shut down and police scoured the city, Reuters reported.
Interior Minister Karl Nehammer told a morning news conference that police shot dead a heavily armed attacker who was a sympathizer of ISIS (the terrorist group banned in Russia).
"We experienced an attack yesterday evening from at least one Islamist terrorist," he said, adding that authorities could not rule out that there were more perpetrators.
Some 1,000 police officers have been deployed across Vienna in the wake of the shootings, which began late Monday outside the city's main synagogue. Police said there were "suspects armed with rifles in six different locations" across the city.
"It is the hardest day for Austria in many years. We are dealing with a terror attack the severity of which, thank God, we have not experienced in Austria in many years," Nehammer told a news conference.
Austria’s capital had so far been spared the kind of deadly militant attacks that have struck Paris, London, Berlin and Brussels, among others, in recent years. Chancellor Sebastian Kurz said the “repulsive” act was “definitely a terror attack”, but he could not say what the motive was.
Border checks were being reinforced, the Interior Ministry said, and children would not be required to attend school on Tuesday. Although people were urged to stay indoors Vienna Mayor Michael Ludwig told broadcaster ORF the city would run normally on Tuesday, albeit with a tougher police presence.
Austrian Chancellor Sebastian Kurz said the shootings were a terror attack, adding that the army would protect sites in the capital so the police could focus on anti-terror operations.
"We are currently experiencing difficult hours in our republic. I would like to thank all the emergency forces who are risking their lives for our safety, especially today. Our police will take decisive action against the perpetrators of this repulsive terrorist attack," Kurz said on Twitter.
The chancellor will hold a special meeting with his cabinet via video conference on Tuesday at 9 am (08:00 UTC). He will then address the nation at 10 am, news agency APA reported.
The head of Austria's Jewish community, Oskar Deutsch, said on Twitter that it was not clear whether the city's synagogue had been the target of the shots fired, but that it and adjoining offices were closed at the time.
"Upon hearing some shots downstairs, I looked down the window and I saw the attacker running into various bars and restaurants…and people running away," said Rabbi Schlomo Hofmeister, an eyewitness to the attack.
"There were one or two attackers chasing them all over the street," he said.