Austrian officials say they are baffled to explain a UFO sighting in which dozens of people reported seeing between 50 and 100 objects flying in formation.

The incident happened over the Aichfeld basin near the city of Knittelfeld in the southern Austrian state of Styria where eyewitness Juergen Trieb, 41, and his girlfriend Waltraud Kaliba, 40, managed to take this snap before the high speed objects vanished.

Waltraud said: “At first we thought it might be some kind of natural phenomenon, but when we realise they were flying in formation and travelling around 400 mph it was clear that it could not be dismissed as something natural. The strange thing was that despite the bright lights there was no noise at all from the objects.”

Local media reported that the images as taken in this snap were seen by several people, and that there were between 50 and 100 of them all flying silently and in formation.

Austrian air traffic controllers said that they had been made aware of the incident and were looking into it, but declined to comment at this stage. But they confirmed there was no indication that the photo or the reported sightings were a fake.

The area over the Aichfeld basin however has been a hot spot for UFO sightings and mysterious atmospheric phenomena, although neither scientists nor UFO watchers have offered an explanation as to why.