A 13-year-old boy is critically ill in hospital with a head injury after being hit by a police van.
The marked vehicle struck the teenager in Swinton, Salford, yesterday while its driver was responding to an incident.
"The boy suffered a head injury, was taken to hospital by ambulance and remains there in a critical condition", a spokesman for Greater Manchester Police said.
The crash occurred at 6.20pm as the officer was driving along Chorley Road in response to an incident in Little Hulton.
The officer has been suspended from driving duties while inquiries are carried out, police said.
A spokesman added: "Officers from the Forensic Collision Reconstruction Unit are examining the scene and GMP's Professional Standards Branch are aware and have informed the IPCC."
Assistant Chief Constable Ian Wiggett said: "Our thoughts are with the family of this little boy and we are devastated that while responding to try and help one person, another has been injured.
"We are carrying out a full investigation into the circumstances of the collision so we can establish exactly what happened."
Anyone with information is asked to call 0161 856 7201.