Local media were also sent dozens of pictures by people who spotted and photographed the strange craft seen hovering illuminated above the city.
The bright flying object was also reportedly seen in other cities in the country, including the southern city of Graz.
Many online commentators however were quick to dismiss those who claimed it was a UFO, saying it looked more like a large quadrocopter, a small multirotor helicopter that is lifted and propelled by four rotors.
Officials have made no comment yet as to the cause of the sightings.
It was not the first time a UFO sighting has caused some consternation in Austria. During a New Year's Eve celebration at the beginning of this year, a UFO that was apparently struck by lightning was taped on video by Marie Mela, a student from the Mostviertel area in the state of Lower Austria.
The video shows a group of people dancing and celebrating the night, when the camera follows some fireworks being shot in the skies. The camera then spotted a brightly glowing orb in the sky that seems to get struck by lightning.
The video was never properly explained, although on that occasion too many people were sceptical that it had been staged.
They said the worried expressions of the students that seemed to be faked underlined that the incident was a fake.
Story courtesy of Central European News.