Police, fire and education chiefs fear lives could be lost as youngsters run amok on derelict Bradford school sites.

As schoolchildren enjoy Easter holidays, the authorities today pleaded with parents to keep them away from "death-trap" buildings, often the scenes of arson attacks and vandalism.

And the warning came with the promise of firm action against anyone who attacked fire crews called out to the former school sites.

Officers tackling a blaze at the former Eccleshill Upper School site were recently pelted with stones by a group of school-aged thugs.

Paul Daly, senior operations manager for West Yorkshire Fire Service, said: "Fire fighters' work is hazardous enough without having to contend with this."

He stressed that attacks could delay officers in dealing with real emergencies, ultimately leading to a loss of life.

Mr Daly added: "Cameras mounted on fire engines will be used to film the culprits and will be passed to police."

Mr Daly also warned children to stay clear of former school sites, closed under the shake-up of Bradford's education system, to avoid injuring themselves.

He said: "Some buildings are boarded up, making getting out of them very difficult, particularly if there was a fire."

Fire crews were recently called to a large fire at the former Undercliffe School site - the latest in a string of arson attacks there.

Superintendent Mark Whyman, of Bradford North Police, said: "We are concerned about the number of incidents of vandalism and arson at local disused schools and take very seriously reports of attacks on local firefighters.

"Not only are these children and youths committing serious crimes they are endangering their own and other lives. I urge parents to monitor their children's movements."

And he added: "Any information on those who have been involved would be gratefully received."

A spokesman for Bradford Council echoed the warning, highlighting that sites such as Eccleshill are being demolished, making them more dangerous.

Councillor David Ward, executive member for education, said: "The demolition work is due to continue there for several months and parents need to be aware of the pitfalls of children playing in what is a potentially very dangerous area.

"We are extremely concerned for the safety of children playing on vacant school sites."