Image: BNS (@Breakingservice)

VIENNA: Three people were seriously injured in a knife attack in the Austrian capital Vienna on Wednesday evening, the Austrian Press Agency (APA) quoted a police spokesman as saying.

Mass-circulation daily newspaper Oesterreich said the stabbings ? which took place around 7:45 PM local time ? occurred in the Leopoldstadt district near Vienna?s famous Prater Park.

News website heute.at said the victims were a man and two women aged between 40 and 50. It is also being said the victims were a couple and their daughter, all of whom have been moved to a hospital after being attacked outside a Japanese eatery.

Other media outlets also reported similar attacks right after the first, although none of the subsequent ones has been confirmed by the authorities.

According to the Washington Post, a "fourth person was attacked with a knife nearby shortly afterward", with the police saying: ?A link (between the attacks) is part of ongoing investigations.?

On the other hand, CNN said area resident Michael Eisenriegler saw flashing lights and went downstairs.

"There were maybe ... one or two dozen policemen (at the site of the attack.) And they are still there," he said, as per CNN.

"(The road) is blocked. They are searching."

APA said police were searching for a lone assailant who had fled the scene, and that the motive for the attack was not known.

The police were not immediately available for comment.

As of publishing time, eight emergency response vehicles had responded to the scene, with the manhunt expanded to "Kärntner Straße and Danube Canal", The Sun reported, adding that trains were also "temporarily redirected as a precautionary measure".

?This is a developing story and will be updated as more information is made available