Venus could be playing tricks with the light over northern Iran

State television has shown pictures of a sparkling white disc which it says was filmed over Tehran on Tuesday.

Other UFOs have been spotted in several northern and north-western cities moving quickly through the atmosphere emitting brightly coloured rays.

Scientists say the sightings are a result of natural phenomena, but many people say they are spy planes.

A reporter for the Irna state news agency observed a UFO last week for 90 minutes in the northern city of Bilesavar and was able to film it, according to a report in the newspaper Hambastegi.

The UFO was spherical and had two arms, the paper said.

'Not experts'

But Sadollah Nasiri-Qeydari, head of Iran's Astronomical Society, has dismissed the possibility that Iran may be being buzzed by alien craft.

"The people who have seen these things are not experts - farmers, villagers and pilots," he said.

He said the sightings were consistent with the planet Venus in its current position.

Its intense light would be given different hues by being filtered through the atmosphere, he said.