POLICE forces throughout the North-East and North Yorkshire yesterday joined a national campaign to reduce the number of knives and offensive weapons in circulation.

The launch of the amnesty came hours before a 38-year-old woman was stabbed to death on a busy city centre street.

Police launched a murder inquiry after Sharon Bell, of Elswick, was found unconscious outside an amusement arcade, in Nelson Street, Newcastle.

Officers were called to the scene at 4.50pm on Tuesday, where they found Ms Bell.

She was taken to Newcastle General Hospital where she later died of her wounds. A hunt for the attacker has begun.

The five-week knife and firearms amnesty is an opportunity for people to dispose of weapons safely by handing them in at police stations without fear of prosecution, provided they have not been used in a crime.

Durham Constabulary hopes the amnesty could also cut the number of air weapon incidents.

Last month, a senior Durham officer warned that people carrying air guns put themselves in potential danger as they risk sparking an armed response from police.

Inspector Ken Cook, of the force's operation division, said: "Without close examination, it is often impossible to tell whether a weapon is fake, an air gun or a more powerful firearm and calls to police from concerned members of the public who have spotted a weapon will generate an armed response.

"A similar reaction would be triggered by incidents involving bladed weapons."

The safest way to carry knives to collection points is to wrap them in cardboard or thick paper.

And while it is accepted that hardcore offenders are unlikely to surrender their weapons, previous experience has shown that items such as flick-knives, swords and daggers will be handed in, along with common items such as craft and kitchen knives.

Cleveland Police ran a weapons amnesty in November last year which resulted in over 100 bladed weapons been handed in.

The campaign is backed by the mothers of two victims who died two years ago - each the result of a stabbing.

Barbara Dunne's 31-year-old son, Robert, was stabbed with a samurai sword yards from his home in West Lane, Middlesbrough, in January 2003.

Theresa Cave is the mother of 17-year-old Christopher Cave, who was stabbed in a flat in Burnmoor Close, Redcar, east Clevelan, in June the same year. She said: "I feel strongly about the need for change in young people's attitudes to carrying knives."