An inquiry is under way after police officers from Nottinghamshire fired baton rounds at a teenage suspect.
Armed response officers were called to reports of an argument in Stanton Hill, Nottingham on Friday night.
A 16-year-old youth was found with a gun, and the officers fired when the teenager move towards them.
The youth was struck but not seriously injured. The Independent Police Complaints Commission (IPCC) confirmed the incident had been referred to them.
The IPCC will now decide whether to conduct a formal investigation.
A spokesperson from Nottinghamshire Police said an independent investigation by the force's Professional Standards department would also begin.
After the baton rounds were discharged, the youth was immediately arrested and taken to Kingsmill Hospital.
Nottinghamshire Police described baton rounds as a "less lethal" type of bullet made from rubber, used to disarm suspects.
He has since been released from hospital and is in custody at Mansfield Police Station.
This is only the second time shots have been fired at a suspect by Nottinghamshire Police. The first was after a siege at a flat in Cotgrave in 2004.