A mysterious light display appearing over Norway last night has left thousands of residents in the north of the country baffled.
Witnesses from Trøndelag to Finnmark compared the amazing sight to anything from a Russian rocket to a meteor or a shock wave - although no one appears to have mentioned UFOs yet.
The phenomenon began when what appeared to be a blue light seemed to soar up from behind a mountain. It stopped mid-air, then began to circulate.
Within seconds a giant spiral had covered the entire sky. Then a green-blue beam of light shot out from its centre - lasting for ten to twelve minutes before disappearing completely.
The Norwegian Meteorological Institute was flooded with telephone calls after the light storm - which astronomers have said did not appear to have been connected to the aurora, or Northern Lights, so common in that area of the world.
The mystery deepened tonight as Russia denied it had been conducting missile tests in the area.
Fred Hansen, from Bø in Vesterålen, described the sight as 'like a big fireball that went around, with a great light around it again.'
He said: 'We saw it from the Inner Harbor in Tromsø. It was absolutely fantastic.
'It almost looked like a rocket that spun around and around and then went diagonally down the heavens.
'It looked like the moon was coming over the mountain, but then came something completely different.'
What could it be? Astronomers say the spectacle did not appear to have been connected to the aurora, or Northern Lights
'It was like a giant spiral - a shooting star that spun around and around. I initially thought it was a projector', added Axel Rose Berg, from Alta.
Celebrity astronomer Knut Jørgen Røed Ødegaard told VG Nett he had never seen anything like the lights.
He said: 'My first thought was that it was a fireball meteor, but it has lasted far too long.
'It may have been a missile in Russia, but I can not guarantee that it is the answer.'
Air Traffic control in Tromsø claimed the light show lasted for two minutes, but admitted that was 'far too long to be an astronomical phenomena.'
Tromsø Geophysical Observatory researcher Truls Lynne Hansen was certain the light had been caused by a missile launch.
He told Norwegian media that the missile had likely lost control and exploded. The spiral, he claimed, was the result of light reflecting on the leaking fuel. He was quoted as saying the light was sunlight, despite the strange lights showing up at night.
The Barents Observer quoted Norwegian Defence spokesman Jon Espen Lien as saying that the Norwegian military does not know what the lights were - but that they were probably from a Russian missile.
He said it was normal for Russia to use the White Sea and the Barents Sea as a testing ground for missiles.
However a Moscow news outlet tonight quoted the Russian Navy as denying any rocket launches from the White Sea area.
Norway should be informed of such launches under international agreements, it was stressed.
The Russian Defence Ministry was unavailable for comment last night.