A man has died in a police shooting during an operation near the M62 motorway.
West Yorkshire Police said a police firearm was discharged at about 18:00 GMT on Monday in Huddersfield.
A police spokesman said five people were arrested as a result of the operation, including three during the incident on the M62. The case has been referred to the police watchdog.
Junction 24 of the motorway remains partially closed.
Those arrested required hospital treatment for injuries “not related to firearm discharge”, the spokesman said.
No officers were injured in the incident.
A West Yorkshire Police spokesman said: “During a pre-planned policing operation near to the M62 in Huddersfield a police firearm was discharged and a man has died.
“An immediate referral has been made to the Independent Police Complaints Commission, who are in attendance in West Yorkshire, and West Yorkshire Police are fully co-operating with their investigation.”
He said two of the five arrests were made during a second vehicle stop in the Chain Bar area of Bradford, also at about 18:00 on Monday.
The force said neither incident was terrorism related.
At the scene: BBC reporter Nick Garnett
West Yorkshire Police is calling it a “pre-planned operation” and, looking at the number of police vehicles involved, it is fairly clear this wasn’t a response to something the force did not know about.
The operation appears to have been planned around one car – believed to be an Audi.
It appears to have been heading off the M62 at around 17:30 GMT on Monday, heading towards Huddersfield, when it was stopped by at least one unmarked police car that was following it.
The car that was stopped, which is still there this morning, was boxed in. Shortly after this a shot was fired and a man died.
A close-up photo shows the marks from what appears to be three bullets in the Audi’s windscreen and a side window that has been smashed.
Eyewitness Rahul Tandon, from Halifax, told BBC Radio Leeds he was stopped by police on the exit slip road of junction 24 as the incident happened.
“As we pulled off the motorway we could see a lot of police vehicles, a lot of flashing lights,” he said.
“We were basically the first car that was stopped by police and we just waited and waited.”
Mr Tandon added: “Over the next 10 to 15 minutes there was frenetic activity as more and more police vehicles arrived.
“At about 6.15 to 6.20, policemen were running up the slope to an ambulance and beckoning them to come quickly.”
He said the police eventually told him and other drivers to leave the scene by reversing up the slip road and back on to the M62.
The BBC’s home affairs correspondent, Danny Shaw, said the incident was the fifth fatal police shooting in England and Wales in the past nine months and the first involving West Yorkshire Police since December 2010.