By DPA,

London : Secret files about the sighting of Unidentified Flying Objects (UFOs) over Britain were opened to the public for the first time Wednesday, arousing anew the interest of "sceptics and believers", officials said.

The information, recording among many others a saucer-shaped UFO hovering over Waterloo Bridge in London, is based on details kept by police stations and airbases around the country.

It is being published by the National Archives in Kew, near London, which has kept the information secret for the past 30 years in line with legislation.

However, the Ministry of Defence (MoD) in London said it was not investigating the possibility of visitors from outer space making a stop at Earth.

Its main interest lay in checking that "UFOs were not in fact signs of earthly covert spying missions by other countries," a statement said.

Nick Pope, who was responsible at the MoD for investigating the sightings said: "While there's no evidence of little green men in these files, they should be of immense interest to sceptics and believers."

Most of the UFO sightings were probably misidentifications of aircraft lights and meteors, but some are more difficult to explain, and include UFOs seen by police officers and pilots, and cases where UFOs have been tracked on radar, he said.

Over the next four years more than 150 files will be thrown open. But those hoping for proof of little green men will be disappointed, according to the MoD.

"The Ministry of Defence does not deny that there are strange things to see in the sky. It certainly has no evidence that alien spacecraft have landed on this planet," a memo dating back to 1983 said.