A 13-year-old boy has suffered a head injury and is critically ill in hospital after being hit by a marked police van.
The crash happened in Swinton, Salford, as the driver was responding to an incident in Little Hulton.
The officer, who was travelling along Chorley Road around 6.30pm on Saturday, has been suspended from driving duties while inquiries are carried out.
"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.
He 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."Source