A man has died after being shot by a firearms officer during an incident in Luton, Bedfordshire Police said.
Officers were responding to reports a woman had been assaulted at a property in Tracey Court, off Hibbert Street at about 1.30pm on Wednesday.
Specialist armed officers also attended and during the incident a 24-year-old man was shot by an officer.
He was treated at the scene by officers and paramedics and taken to hospital but was pronounced dead at 2.50pm. His next of kin have been informed.
Bedfordshire Police have now referred themselves to the Independent Police Complaints Commission (IPCC) which has begun an investigation following the fatal shooting.
Chief Constable Jon Boutcher said: "First and foremost our thoughts are very much with the family of the man involved in this tragic incident.
"The IPCC has been informed, as is standard protocol when someone has died following police contact, and as such it would be inappropriate for us to comment any further at this stage."
An IPCC spokesman said: "Investigators have been sent to the scene and to the post-incident procedures where initial accounts will be provided.
"Investigators have also been sent to the hospital to make some initial inquiries. The man's next of kin has been notified by Bedfordshire Police and the IPCC will be contacting them to inform them of our role.
"The investigation is in its early stages and no further information is available at this time."