Police investigating a hit and run incident which left a two-year-old boy and his 10-year-old sister fighting for their lives have released an image of a car they believed was involved.
Raham Saleem and his sister Sabam were knocked down by a Vauxhall Astra in Brudenell Road, Hyde Park, Leeds, at around 5.20pm on Saturday.
Police said they were hit after buying onions for the family's Eid celebrations.
Officers said the driver slowed down to see what had happened, then sped away from the scene.
The children underwent surgery at Leeds General Infirmary where Sabam remains in a critical condition.
But West Yorkshire Police said her brother was now improving and has been moved out of the intensive care unit.
Now the investigation team has released a picture of a silver or grey Vauxhall Astra mark 4 (1998-2005) they urgently want to trace.
Detectives said they are continuing to trawl through CCTV.
They believe a woman seen on the street at the time may well have witnessed what happened.
Detective Superintendent Paul Taylor who is leading the inquiry, said: "A major investigation remains ongoing into what has been a catastrophic incident for Sabam and Raham's family on what should have been one of the happiest weekends of their year.
"Specialist officers are working to support the family who are clearly extremely distressed, and for their sake we ask anyone who can help us more quickly find the driver responsible for this collision to come forwards now."
"We can now release a CCTV image of the car which we believe was responsible and ask that anyone who recognises this vehicle should contact us as a matter or urgency.
"We also know there was a woman who was on the street at the time who we have not spoken to yet and would ask her to make contact with us as soon as possible."
Mr Taylor said: "We are making progress with this investigation which is drawing on specialist resources from across the force, including homicide officers and our specialist Major Collision Enquiry Team.
"We have received a lot of support from residents who are helping us investigate a truly shocking incident in a very close knit community and are determined to leave no stone unturned to locate this driver.
"Clearly it remains the case that it would be better for this individual to contact us before we come to see them."