LONDON'S X-Files have been opened to the public.
Reports of "lights in a worm shape wriggling around in the sky", a shiny "doughnut-shaped object" and a "massive light in the shape of an iron" are among sightings of UFOs which were meant to have been secret for 25 years.
The files show that Loughton in Essex is the UFO capital of the Home Counties.
The MoD has six sightings listed there - five on the night of 10 September last year, when there was a series of reports of three mysterious orange lights in the sky.
The sightings in Greater London, dating from 2002 and kept on Ministry of Defence files, have been released after a request under the Freedom of Information Act by the Evening Standard.
The MoD receives hundreds of reports of sightings every year, most of which are dismissed as aircraft lights or natural phenomena.
But some have no rational explanation, and as a result, the Government remains "totally open-minded" about the concept of flying saucers and spaceships.
Following the Standard's request, the MoD's UFO department - SF4 - revealed details of 34 sightings with their date, time and location.
Among them are descriptions of "a black cigar-shaped object which accelerated to a speed which would outstrip a fighter jet" over south-east London and a "rectangle-shape white light" hovering above Primrose Hill.
Nick Pope, who ran the Government UFO project between 1991 and 1994, said the data was unsurprising. He said: "London has the most sightings because there are more people living there to witness any unusual activity.
"Almost 95 per cent of sightings can be explained away but that still leaves five per cent. I am not out to spook anyone but I do believe it is totally feasible that we are not alone in this universe."
One of the witnesses, Robert Sloan, said: "There was a triangle of three piercing globes. It reminded me of a scene out of Close Encounters. Everyone was gobsmacked.
There was no way a plane would look or move that fast."
Other UFOs spotted include three over St John's Wood, two over Hornchurch, Essex, and three over Wimbledon.
Timothy Good of Beckenham, an author of several novels on UFOs, said: "UFOs remain the most sensitive subject in British intelligence. It is wonderful that some of this information is now being made public even though I believe they are withholding even more.
"The sheer number of sightings over London and the fact that none has a rational explanation is both fascinating and exciting to me."
An MoD spokesman said there was nothing to suggest alien activity.
"We examine reports of UFOs solely to establish whether there is any evidence that the UK's airspace has been compromised by hostile or unauthorised air activity," he said.
"We do not know of any evidence which substantiates the existence of these alleged phenomena."
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