Detectives investigating the shooting of a Sheffield taxi driver have released photos of six vehicles they want to trace.
Two of the cars police want to trace that were in the area at the time
Father-of-five Younis Khan, 53, was shot as he drove along Scott Road, Pitsmoor, Sheffield, on 14 March.
Police said the vehicles in the CCTV images were in the area about the time Mr Khan was killed.
They said the cars' drivers and passengers could be vital witnesses to the incident.
Det Supt Martyn Bates, of South Yorkshire Police, said none of those in the pictured vehicles was under suspicion and he believed Mr Khan's killers had been in another car.
'Treated in confidence'
Det Supt Bates said: "The enquiry is progressing well and we are pleased with the way it is going.
"But we are still appealing for witnesses, and I want to assure people who have information, especially about the vehicles captured on CCTV, that they will be treated in confidence."
All the CCTV images are available on South Yorkshire Police's website.
A post-mortem examination revealed Mr Khan, who also had five grandchildren, died from a single gunshot to the chest, fired from a handgun.
Mr Khan's Hackney cab crashed into two parked cars after he was shot.
It is believed he lost control of the vehicle because of his injuries.