A squad of police officers last night raided a suspected brothel in the heart of Bradford as part of a campaign to clamp down on the vice trade in the city.

The team of 15 uniformed and plain-clothes officers targeted the Mercedes Health Spa after a series of complaints and tip-offs from members of the public.

Sgt Simon Beldon, who headed last night's operation and is part of the force's Vice Squad, explained that the three-storey building, in Little Horton Lane, had recently been hit by two arson attacks, making it necessary to execute the warrant immediately.

At the mission briefing, he and the team of officers were told that up to six alleged prostitutes might be working a shift system from the premises, which was thought to be run by a middle-aged woman for its owners.

At around 7pm yesterday, the 15-strong squad carried out the raid but found just four women inside.

One woman in her fifties was arrested on suspicion of procuring women into prostitution and managing a brothel.

Three other women - who covered their faces as they left by the front door - were 'spoken to' by officers but released without charge.

Sgt Beldon said the operation helped send the message that prostitution would not be tolerated.

Since the vice squad was formed a year ago, around 100 kerb crawlers have been arrested and 150 letters sent home to those seen 'cruising' in the red light areas. More than 50 prostitutes have been brought to court with around another 50 being cautioned.

"Many prostitutes are reliant on working to fund drug habits and are being exploited by others," he added, "While there is a strong presence of street prostitution in Bradford, there are still a number of brothels masquerading as massage parlours."

But he said Bradford's problem was no worse than any other city's, even though television programmes such as Band of Gold portrayed it as the 'prostitution capital of the North'.

And he said: "Through the work of the vice squad the situation is getting better. The clear message is that if you want to involve yourself in this type of activity then don't come to Bradford because you will be caught."

Yesterday's raid came as part of Operation Gosport, a week-long offensive by Bradford's robbery and vice squads against prostitution and street crime.

Within four days of its launch more than 50 people were arrested and 40 warning letters sent to people seen kerb crawling in red light areas.