Detectives are hunting robbers who snatched thousands of pounds from a businessman after driving into the back of his car.
The same gang is thought to have been responsible for mugging a woman employee in the street - punching her in the face - only 90 minutes later.
The two attacks, targeting business people taking cash to be deposited, happened within a few hundred yards of each other in Lidget Green, Bradford.
Police are seeking a silver Volkswagen Golf which is believed to have been used in both incidents.
The first robbery took place shortly after 10.20am on Monday as the 65-year-old owner of a local business was driving in Horton Grange Road, near to Ingleby Road, to the bank. He was travelling slowly when the silver Golf hit the back of his vehicle.
The victim got out and an Asian man from the silver car also got out and engaged him in conversation, before striking him in the chest.
Another man then grabbed a bag of cash from in the car. The robbers drove off in the silver car.
The second incident happened at about noon as two women employees were walking a short distance from their convenience store to the post office in Beckside Road, each carrying a bag of cash.
An Asian man, with his face covered by a balaclava mask, ran up and ripped the bag from one of the women. He ran off down the street and the women gave chase, but the robber turned round aggressively and punched one of them, aged 25, in the face.
He then dived into the back of the waiting silver car, which contained at least two other men. The robber was in his mid 20s, of medium build, about 6ft tall, and was wearing blue jeans and possibly a black and grey hooded top.
Neither victim was injured but more than £20,000 in total was stolen in the robberies.
Detective Inspector Tony Nicholson, of Bradford District CID, said it had been a deliberate ploy to drive into the back of the businessman's car, in order to get him out of it. He said it was possible the gang had kept the businessman under surveillance before the robbery.
He said: "Due to the description of the vehicle used in both these incidents, and the times and area in which they occurred, we are treating them as linked.
"We are keen to trace this vehicle, which is believed to be a silver saloon-type car with a '52' plate, as well as the people who were travelling in it.
"It appears that the victims were targeted because they were known to be carrying cash at the time, so it is possible these men will have known something about their movements.
"I would also like to urge businesses who need to transport cash from their premises to consider different methods of doing so, perhaps by varying the times of their trips or by going in pairs."
Anyone with information about the men, or the vehicle, should contact Detective Constable Milburn, at Bradford District CID, on 101, or Crimestoppers, anonymously, on 0800 555 111.