Pokemon is the playground craze of the moment - and what began life in Japan as a hand-held Nintendo game four years ago has now become Pokemadness.

The Pokemon empire has grown into a five billion dollar industry worldwide and has ensnared children in Japan, the US and Britain with its computer games, toys, sweets and trading cards.

The film, Pokemon - The First Movie, took £6 million on its opening day in America and Warner Bros hopes to sell 3.5 million tickets here when it opens on April 14 during the Easter holidays.

If it really is the first film of many, the news will send shivers down every parent's spine.

What worries parents and teachers most are the cards. For the uninitiated, the object is to collect all 151 cards

featuring the different Pokemon monsters.

Although on the surface it is no different to collecting cards of a favourite football team, children are apparently now obsessed by buying and collecting, and particularly finding a rare card.

Packs of 11 cards should sell for £2.45 but cards can change hands for as much as £30, while on Internet auction sites, bids of £300 are not unheard of for really desirable cards.

The high value cards are distributed randomly throughout the packs, so kids who hand over their pocket money could find 10 practically worthless cards plus one high in value - or 11 cards he or she already owns.

Stories are now emerging of bullying, intimidation and "aggressive trading" among those desperate to get their hands on a rare card.

Schools around Wharfedale have banned the trade.

For example, at South View Junior School, Yeadon, children are not allowed to bring the cards to school. But head mistress Alison Anslow says this is simply to avoid confusion if the cards get dropped and children end up

squabbling over who owns what.

At Prince Henry's Grammar School, Otley, the cards have been banned from the library and press officer Sian Ellis said every breaktime, younger pupils could be seen swopping them, talking about them and squabbling over who had agreed to swop with who.

For schools throughout the country, stories from America last year should have acted as a warning.

US police denounced the cards as "America's most dangerous hobby" after a surge in child crime.

Six children were arrested in Philadelphia for a Pokemon-related assault.

Nationally the hobby seems even more popular than it is in Wharfedale.

Liz Paver is head of the Intake Primary School in Doncaster and, like other head teachers, has banned the Pokemon cards.

"They are quite expensive items and a week or two ago, I stopped a boy who had £30 worth in his pocket. We are not an affluent area and that's an enormous amount of money. I don't think manufacturers take into consideration the conflict these things bring about.

"Pokemon has got completely out of hand, really. Children have always collected cards and put them in albums. Collecting is a human instinct and it's something we value with children, but are these really worth valuing to the extent that it causes sleepless nights? This craze has been another vehicle by which power has been wielded by some children."

Michael Chitty, head of Ashfold prep school, near Thame in Oxfordshire, expects pupils to police themselves but there is a policy of no swapping between junior and senior schools.

"This has prevented any aggressive swapping, as a young child isn't likely to say no to an older one, and there also have to be two other people present when the swap takes place."

The teachers' complaints about thoughtless toy manufacturers are rejected by Jon Salisbury, editor of UK Toy News. He admits that while sales of Pokemon are extremely healthy, the anti-social aspects of the game can be controlled.

"It's like any desirable object, it's up to parents to control what their children do about it. The cards are the zenith of the craze. The toys and video games are doing nicely but the cards are the most user friendly things available.

"You could say this is dangerous and we are encouraging children to spend money and be avaricious. Well, aren't we as adults subject to the same temptations? But it's down to parents. I don't think it's socially unacceptable and anyway, the craze could be dead in the water tomorrow."

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.