The Police Ombudsman is to begin an investigation after a vulnerable man was been shot in the chest by police in Londonderry.
It happened at 10.45pm on Saturday 17 April.
The PSNI said officers "responded to a report of concern for safety for a man at an address in Celandine Court in Gobnascale at approximately 10.45pm."
"As officers were dealing with the incident, a police firearm was discharged and the male sustained a chest injury," a spokesperson said.
"He remains in hospital at this time."
A police officer sustained knife wounds to his arm and head during the incident and was taken to hospital for treatment.
The Police Ombudsman's Office has been informed and is investigating.
“Our investigators are at the scene and are making enquiries to establish the circumstances of what happened," a statement said.
“At this stage, we know that police went to the flat after receiving a call for assistance.
"There was then a confrontation during which one police officer sustained stab wounds and police discharged CS spray and a single gunshot.
“Police notified the Police Ombudsman’s on-call team about the incident, and our investigators have been making enquiries at the scene throughout the night.
“We would be keen to hear from anyone who knows anything about what happened, and would ask anybody who might be able to assist our enquiries to call our freephone witness appeal line on 0800 032 7880."
Sinn Fein MLA Martina Anderson said she is "deeply shocked" and "very concerned" about the shooting of a "vulnerable individual by the PSNI."
Ms Anderson said: "The man is in intensive care in hospital and my first thoughts are that I hope he will survive his injuries.
"A police officer also suffered a stab wound during the incident. Thankfully the officer has been released from hospital and I hope he too makes a full recovery."
She said she has contacted senior police and the Police Ombudsman to convey her "grave concerns that lethal force has been used in this incident."