Two Eastern European women pinned an 84 year-old disabled man against a bus shelter and robbed him of £500 cash after trailing him from a bank.
The suspects (pic. r.) followed the pensioner from the Halifax building society in Liverpool Road, Islington, on November 12, last year and on to a number 30 bus.
They pretended to help him on to the bus and into a seat and made an unsuccessful bid to steal the money from the victim's coat pocket.
The pensioner got off the bus in St Paul's Road, Islington, and when he stopped to rest at a nearby bus stop, the suspects grabbed him and pinned him up against the shelter before stealing the cash.
Both women are described as being of Eastern European appearance.
The first is described as aged about 35, approximately 5'6" tall, well built, with short black hair with a short fringe and the second is described as aged about 55, approximately 5'3" tall, of slim build with long black hair.
The victim, who is from Islington, was very shaken up as a result of the incident.
His daughter, 53, said: "I think it's terrible that they pick on vulnerable people and have resorted to this.
“They seem to be pickpockets who have upped their game. Fortunately, my dad was not physically hurt - the next victim might not be so lucky."
The investigation is being carried out by PC Jo Miller from the Islington Robbery Squad with support from the Visual Images and Identification Office (VIIDO), which specialises in the investigation of CCTV images.
PC Jo Miller said: "I am doing everything I can to ensure that these offenders are brought to justice however so much relies on the CCTV images. If you know who these people are, then please contact us immediately."