A police campaign against vice has dramatically cut the number of violent attacks on prostitutes in Bradford, it was revealed today.

In four years, almost half the attacks on prostitutes in West Yorkshire happened in Bradford, including 21 rapes.

But since the start of the vice crackdown last year - called Operation Red Light - the tally has tumbled, according to Detective Superintendent Geoff Dodd.

There were 43 violent attacks on prostitutes in Bradford from August 1997 to last May, out of a county total of 101.

The list includes the unsolved murder of 19-year-old prostitute Becky Hall whose battered body was found in Thornton Street on April 26 last year.

And it includes the attempted murder of former prostitute Nicola Jane Hirst who was stabbed 43 times by security guard Noel John Dooley in October 2000. Last year Dooley was jailed for life after he was found guilty of her attempted murder.

The incidents also involve the 21 rapes and six indecent assaults as well as a catalogue of violent robberies.

Most of the attacks happened in the city's red light area around Lister Hills and Thornton Road and Sunbridge Road - a popular haunt of kerb crawlers and pimps.

But Det Supt Dodd said the formation of the city's vice squad last August had helped to cut the number of attacks on prostitutes.

New legislation in October - which made kerb crawling an arrestable offence - had also been an important deterrent.

"In four years we've had 43 reported crimes. These are serious attacks against working women - that cannot be right.

"Many women are controlled by pimps, either through force or by drugs, and that cannot be tolerated.

"Many men who use prostitutes have convictions for violence and use violence against these women and that cannot be tolerated either.

"Since the first week that the new powers of arrest for kerb crawling came in, it meant my officers were able to deal far more robustly with kerb crawlers.

"We have been able to arrest them, obtain a photograph, finger prints and a DNA sample from the suspect as part of the arrest process. This is an powerful deterrent.

"For example a man who has no criminal record decides to rape a prostitute, which as you see from the figures can be a common occurrence. The woman reports the crime and samples are taken.

"If he is not caught then maybe the same man is arrested weeks, months or years later for kerb crawling.

"He will run a strong risk of being identified as responsible for the rape because of the DNA sample taken as part of the new legislation."

Det Supt Dodd said a change in the way police handled crimes committed against prostitutes had led to most serious offences being reported.

He added: "We are not complacent in any way and there is a lot more to do. The vice team is not going to go away.

"We are continuing to target kerb crawlers and pimps and we will continue to encourage working women to exit the lifestyle of prostitution - but we will arrest and charge persistent prostitutes and take them to court."

Since the new legislation was introduced Bradford vice officers have arrested 30 kerb crawlers and closed down two massage parlours being used as brothels.