It's old, it's simple and there isn't a computer chip in sight - the latest schoolyard craze is the ancient art of diabolo.

Pupils at Balfour Junior School, Brighton, have become experts in the art of tossing, twisting and teasing the hourglass-shaped toy.

More than half the 420 pupils have their own diabolo, which is rolled and thrown along a length of string between two sticks.

The craze has taken such a hold that Thursday was made Diabolo Day, with French high-throw champion Zanzibar - real name Julian Bouley - performing throwing tricks and bubble-blowing.

Acting head teacher John Vousden said diabolo fever began before Christmas when Year 6 pupil Louis Brooks brought one to school.

He said: "Louis asked if he could use it at playtime and I said yes. It has snowballed from there.

"Sometimes we've banned crazes from school because they are not suitable. But this one has worked well."

Louis, ten, caught the diabolo bug from his cousin, who brought it over from New Zealand.

He said: "I've told him it has started a craze and he thinks it's cool."

Teacher Trisha Waters said: "Diabolo requires focus and concentration and is ideal for hand-eye co-ordination.

"Rather than cause problems, it has improved playground behaviour because the children are eager to show each other moves and tricks."

Diabolo was invented in China between the 4th and 3rd Century BC. The name comes from the ancient Greek "dia" for through and "ballo" for throw.

It became fashionable among the Parisian upper classes in 1810, where clubs and competitions sprang up. Many Victorians also adopted it as a pastime.

In 1906, Gustave Philippart invented a diabolo made of metal and rubber.

It was rediscovered in the Eighties when newer materials and greater precision in manufacture meant a wider range of tricks.