Multiple people have died in a crash involving a police vehicle and a car, police have said.
The collision involved a police vehicle and a Volkswagen Passat on the A66 in South Bank, near Middlesbrough in Teesside, at about 03:39 BST, Cleveland Police said.
North East Ambulance Service said 14 "ambulance resources" attended and "a number of patients died at the scene".
A police spokesman said: "Sadly, the collision has resulted in multiple fatalities. We are working to identify the victims and contact their families."
A police van and a car could be seen at the east side of the road with lights flashing, with two police officers standing at the scene.
The A66 is the major artery through Teesside and the location of the crash is surrounded by industrial units and factories.
The road remains closed in both directions between Normanby Road and Church Lane and the force said it was set to stay closed for the rest of the day.
Motorists have been advised to use alternative routes.
The force said there were still "significant emergency service vehicles" on the scene.
It added: "This is a quickly evolving incident and we ask that members of the public respectfully avoid speculation."
The North East Ambulance Service said: "Sadly, despite the best efforts of everyone attending, a number of patients died at the scene," the service said.
"We send condolences to all of those affected by such a tragic event and thank everyone for all they did to help."
-BBC
