An amnesty to rid Bradford's streets of potentially deadly weapons has been backed by the widow of a headteacher stabbed to death outside his school.

People who own knives, coshes, swords or even guns, have been urged to dump them anonymously in special wheelie bins which will be placed at police stations for the coming months.

Launching the countywide campaign yesterday, West Yorkshire Police's Chief Constable Graham Moore said: "Every offensive weapon in public hands is potentially lethal. People can literally save lives by disposing of items now".

Every year, 4,000 incidents occur involving offensive weapons across West Yorkshire. The disturbing figures show that an offensive weapon is used in a crime or found in someone's possession 76 times per week.

"Every single incident has the potential for serious injury, or death," said Mr Moore.

He highlighted how items such as swords kept as souvenirs often fell into criminal hands as the result of burglaries.

His comments were supported by Frances Lawrence, whose husband Philip was killed in 1995 as he tried to stop a scuffle outside his London school.

Mrs Lawrence said: "When my husband, Philip, was fatally stabbed outside the gates of his school, I experienced the utter devastation caused by the use of a knife. Since then I have seen how vulnerable we all are."

She pleaded for youngsters not to carry weapons, even if they felt it was for self-protection.

"To many young people it is now a normal expectation that others carry weapons and that therefore they should.

She added: "In doing so, they put not only others at risk, but themselves also.

"It is difficult to alter this expectation - but because something is difficult, it doesn't mean that we shouldn't try to find a solution."

And she said: "The murder of my husband was an act of the utmost brutality that destroyed the centre of my family. It was also an act of supreme cowardice that destroyed the future of the young man who stabbed him."

She added: "The amnesty gives people a choice - they can keep their weapons and risk destroying their own lives. Or, they can give them up anonymously, thereby ensuring that their community is a safer one for others and for themselves."

Up until midnight on February 11, weapons can be placed in bins at police stations at Eccleshill, Toller Lane, Bradford South (The Tyrls), Odsal, Keighley and Pudsey.