By Chris Hogg

BBC News, Tokyo



Mr Machimura's comments might not have been serious

Earlier, in response to a question from an opposition lawmaker, the Japanese government issued a statement saying it could not confirm any cases of UFOs.

But Chief Cabinet Secretary Nobutaka Machimura later told reporters he believed they were "definitely" real.

It is the sort of question politicians dread but, under Japanese rules, are unable to ignore.

A member of the opposition asked the government what its policy was to deal with UFOs.

He said work should begin urgently to try to confirm whether or not they exist because of what he called "incessant" reports of sightings.

The Japanese civil service swung into action.

In a statement it said that should a flying saucer be spotted in the country's airspace, a fighter would be scrambled to attempt visual confirmation.

But it emphasised that the government was not aware of cases where a UFO from space had been discovered.

Most alerts turned out to be birds or other objects.

'Not confirmed'

The document revealed that Japan has not yet planned what to do should aliens arrive here.

Many UFO sightings can be easily explained

The government's chief spokesman Nobutaka Machimura drew laughter from reporters when he admitted that this was a "stereotypical" response from the bureaucrats.

Perhaps with his tongue a little in his cheek he insisted that he believed UFOs did "definitely" exist.

Questioned about the existence of alien spaceships, Japan's Prime Minister Yasuo Fukuda thought about it and then answered carefully.

He said he had "not yet confirmed" whether they existed.

The conspiracy theorists will note that the answer was not a "no".