A man's been killed by firearms officers during an incident near Bristol.
The "incident involving police firearms" happened in Portishead, west of London, Avon and Somerset police said.
'I saw them back off from a auto and then they surrounded it and then they shot with handguns five, six, maybe ten times.
David Ellison has told BBC Radio Bristol: "As I came out of Portishead. police were ahead of me".
Onlookers said two police cars pinned in the vehicle, before officers approached, backed off and then closed back in as others fired upon the auto.
"We have referred the incident to the Independent Police Complaints Commission".
Forensic officers have cordoned off the scene at a junction of the M5 for Portishead.
A council spokesman said: "If you are heading home to Portishead tonight either northbound or southbound on the M5 then your best route home is via Clevedon (junction 20) using the B3124 towards Portishead".
Police have confirmed they were scrambled this morning to deal with an "incident" and said the road would be closed for some time.
A red auto at the scene had what appeared to be bullet holes in its side and a handgun on its roof.
The driver's side front window was smashed, and there was blood and glass on the floor as well as a sun hat.
"A statement released by Avon and Somerset Police said, ".The Air Ambulance has landed. "God knows what was happening".
"The vehicle left the motorway at Junction 19 and officers stopped the auto on the A369 known as the Portbury Hundred. Our investigation is in its very early stages".
"IPCC investigators are at the scene gathering evidence and are attending the post-incident procedures".