An alarming spate of arson attacks on Bradford schools is putting children's lives at risk, fire chiefs today warned.

Officers have begun an urgent tour of classrooms throughout the county in a bid to halt a disturbing trend which has escalated to firebugs striking during school hours.

David Firth, Senior Safety Officer for West Yorkshire, said it had seen more than 100 school blazes in the past 13 months - 80 per cent of them the work of arsonists.

In Bradford alone, there were 44 school blazes in 2000 and three more since January 1. Out of ten school blazes countywide this year, six were started deliberately.

Bradford has suffered the added peril of arsonists targeting disused school sites closed under the city's education shake-up. As crews went to tackle a deliberately-started blaze at the Undercliffe School in October last year, they came under fire from missiles hurled by gangs of youths.

Mr Firth said: "There is a worrying trend where fires have been started during school hours. This is a high-priority area for the authority to tackle."

He said that although Bradford had so far escaped serious school time blazes, he believed a number of small scale incidents had occurred.

"We must act now - before there is a terrible tragedy,'' he added.

The brigade is currently working with education chiefs to arrange an urgent series of school visits across the district.

As well as speaking to youngsters about the potentially-lethal effects of fire starting, fire safety officers aim to raise teacher awareness about the problem.

Mr Firth said: "We want to check basic fire precautions, raise teacher awareness and drive home to youngsters the danger about messing around with fire and matches."

And he added: "Parents can help by reinforcing this simple message: Fire kills."