Bradford's schoolchildren will be warned of the dangers of making hoax 999 calls after research found that millions of malicious calls were made last year to the emergency services.

Of the 30 million 999 calls handled by BT nationally, a "staggering" 52 per cent were hoax, misdialled or not appropriate for the police, ambulance or fire brigade.

The district's emergency services have backed the campaign and warned that the bogus calls they received were putting lives at risk.

In 2003, the West Yorkshire Fire and Rescue Service received 5,796 hoax calls and as a result crews attended 2,321 bogus incidents.

Bradford's community safety officer Tony Firth said: "While we are attending these malicious calls, we are unavailable to go to real emergencies.

"This could very well result in injury or even death to those who are in genuine need of a fire appliance and crew.

"At the very least, the cost implication of the unnecessary activation of our resources is something that the majority of the general public do not want. People who make hoax calls should consider the consequences of sending out an emergency crew unnecessarily - it can cost lives."

West Yorkshire Police believes one in every 100 calls is a hoax. Supt Chris Barnes, divisional commander for West Yorkshire which had 800 hoax calls in 2003, said: "Hoax calls can put genuine callers at serious risk as valuable police officers and other emergency services are diverted away. For this reason we will always work to track down hoax callers using the latest technology and bring them to justice. Penalties for this type of offence are severe." BT will visit schools across the UK this week showing a video which warns of the dangers of making hoax calls and urging children to think twice before dialling 999.

Over the next year, in partnership with the fire service they will talk to children about the consequences of hoax calls and show a specially produced video known as Code 6 to educate youngsters.

Hoax calls can carry a maximum penalty of up to three months in prison. The drive is part of BT's hoax call awareness week.