A road near the M5 motorway will remain closed during the morning rush hour after a man died in a shooting involving armed police.
Officers fired shots at a car on the Portbury Hundred (A369) near junction 19 for Portishead at about 09:30 BST on Wednesday, an eyewitness told the BBC.
Avon and Somerset Police said it acted following reports of a man in a car with a handgun.
The road will remain closed throughout the night and during the morning.
A police spokesman added: “This is to ensure all necessary evidence is gathered and a thorough examination of the scene is carried out.”
Avon and Somerset Police said it had referred the shooting to the Independent Police Complaints Commission (IPCC), who confirmed it had launched an investigation.
“We have been advised that officers were responding to reports of a man travelling on the M5 with a handgun and that he had threatened another motorist,” an IPCC spokesman said.
“What appears to be a non-police issue firearm was found at the scene and will also be subject to examination.”
He added inquiries were continuing to formally identify the deceased and his next of kin. A post mortem is due to take place on Thursday.
David Ellison told BBC Radio Bristol he saw officers fire between six and 10 shots through the passenger window using handguns.
“They surrounded it. They shot maybe five, six or 10 times,” he said.
“Then they dragged a man from the car to resuscitate him.
“It came off the roundabout towards Portishead and then was boxed in by cars.”
A police spokesman said the shooting was not terror-related.
“We received calls from concerned members of the public travelling on the M5 who reported they had seen a man in a car with a handgun,” he added.
“The vehicle left the motorway at junction 19 and officers stopped the car on the A369 known as the Portbury Hundred.
“Shots were subsequently fired in an incident involving police firearms and a man has died.”
The Great Western Air Ambulance’s critical care team also attended.
The Portbury Hundred links the M5 motorway to the town of Portishead, to the west of Bristol.
Diversions are in place and police have advised drivers to plan ahead and use alternative routes.