Violent robbers are targeting men who pick up prostitutes and drive them to secluded spots in Bradford, police have revealed.

Bradford North CID are investigating a spate of robberies where men who have picked up prostitutes in the city have been targeted. Three such robberies were reported in the early hours of last Wednesday, two of which involved the victim being punched in the face and one which saw a knife used as a threat.

Officers believe there could be other victims who have not reported incidents.

On each occasion, the victim picked up a prostitute in Manningham and drove to a secluded location where they were confronted by two men and robbed.

At about midnight on Wednesday, a man was robbed of his mobile phone when he parked up in Woodhead Road after picking up a prostitute.

Two men approached his car, opened the doors, threatened him and demanded cash and his phone.

One of the men then punched him on the jaw causing minor injuries. Further threats were made and he was forced to hand over his phone.

Both men were described as Asian, aged 25 to 30 years, with local accents, both wearing black hooded tops with the hoods up.

One was described as slim and the other of medium build, with a full trimmed beard and short black hair.

At about 1:47am, a man was robbed of cash, credit cards, a mobile phone and a jacket, in Conduit Street after picking up a prostitute. Again, two men approached his car and he was punched in the face by one of the men, causing minor injuries. The pair took the property from the vehicle and ran off.

The men were described as Asian, one in his early 20s, about 5ft 9ins tall, medium build, with black hair. He was wearing a black top and jeans.

At about 6am, another man was robbed in Houghton Place after picking up a prostitute. Two men confronted him and threatened him with a knife before taking a wallet, cash and a mobile phone.

One of the robbers was described as Asian, aged 19 to 20, about 5ft 10ins tall, with a local accent, wearing a full balaclava mask, dark jeans and dark trainers. The other man was described as Asian, in his late 20s, medium build, with short dark hair. He was wearing a dark sweater, which was pulled over the lower part of his face.

Detectives are linking all three incidents and believe there may be others that have gone unreported. It is not believed that the prostitutes the men have picked up are involved in the robberies.

Police believe the robbers are following their victims from the Manningham area.

Officers are keen to trace anyone who witnessed any of the incidents or who has any information that could assist in tracing the robbers.

They are also keen to hear from victims who have not yet reported incidents.

Anyone with information should call Bradford North CID on (01274) 376202 or Crimestoppers anonymously on 0800 555 111.