Police constable to give statement this afternoonpublished at 15:32 BST
We now expect Cleveland Police Chief Constable Victoria Fuller to give a statement at about 16:00 BST.
We will bring you the key lines when we have them.
Two police officers are among seven people who have died in a crash involving a police vehicle and a Volkswagen Passat
The collision happened on the A66 in South Bank, near Middlesbrough in Teesside, shortly after 03:30 BST on Saturday
The police watchdog, the IPOC, says it is investigating and understands Cleveland Police "sighted a suspicious vehicle and a pursuit began"
Cleveland Police's Chief Constable Victoria Fuller says the "tragic incident will be felt across Cleveland"
Images show a large emergency services response at the scene - North East Ambulance Service says it sent "14 ambulance resources"
Edited by Caitlin Doherty, Craig Hoyle and Tinshui Yeung, with Philippa Goymer reporting from South Bank
We now expect Cleveland Police Chief Constable Victoria Fuller to give a statement at about 16:00 BST.
We will bring you the key lines when we have them.
Two councillors for the Eston ward where the crash happened say they are "deeply saddened" by the "unimaginable tragedy".
Writing on social media, David Taylor and Stephen Martin share their "heartfelt condolences" with "the families, friends and loved ones of everyone who tragically lost their life".
They say their thoughts are also with Cleveland Police, "the wider policing family" and emergency services who attended the scene.
"This is an unimaginable tragedy that will be felt deeply throughout TS6 and communities across Cleveland and around the country," they say, referencing the wider area's postcode.
"Absolutely heartbreaking," the post adds.
Image source, PA Media
The A66 - a major artery through Teesside - has been transformed into an emergency scene following this morning's fatal collision.
The road remains closed in both directions between Normanby Road and Church Lane in Eston.
It is an area bordered by large industrial units and close to the major Teesworks site, one of the biggest brownfield regeneration sites in Europe.
Officers have been policing both ends of the cordon - the crash site is not visible from the road closures.
Pictures show several emergency vehicles nearby, and a white tent has been erected over the scene of the crash.
Police have put a drone exclusion zone in place.
Philippa Goymer
BBC North East and Cumbria, reporting from South Bank

Cleveland Police are standing at the closure of the A66 as crime scene investigations continue at the major road between Middlesbrough and the Teesside coast.
Images from the accident investigation site show a police tent in place, and parts of a vehicle in the road.
There are a number of police vehicles and Cleveland Fire Brigade at the scene conducting the investigation.
No tributes have been placed at the scene so far but some people passing the road closure have described the incident as “tragic”.
Image source, Getty ImagesHome Secretary Shabana Mahmood pays tribute to police as she responds to the "devastating incident".
"Cleveland Police have my support as they work to identify all those involved," she writes on X.
"Police officers put their own safety on the line to protect their communities every single day.
"My thoughts are with all those affected, their families, friends, the emergency services who attended the scene and the wider police family."
Chair of the Cleveland Police Federation, Lauren Somerville, says "words cannot describe the pain the Cleveland Police family are feeling today".
"Our colleagues who should have been going home to their loved ones at the end of their shifts are not. And that is just unfathomable."
In her statement, published on social media, she says the federation will be offering "full support" to the affected families, adding that they have "all of our love and care at this time".
"When the time is right we will pay full tribute to our brave colleagues. But we can assure that their sacrifice will never be forgotten," she adds.
The Independent Office for Police Conduct (IOPC)'s investigation into the incident remains in its "very early stages", says its director of investigations Nicola Marfleet.
"This is a tragic incident, and my thoughts are with family and friends and all those affected, including the emergency services in attendance," she says in a statement.
She adds that "when someone dies following police contact" it is mandatory that the incident is referred to the IOPC for investigation.
"Our role is to establish and examine the circumstances of what happened; this work is already underway, and Cleveland Police is cooperating with our enquiries," she adds.

Seven people have died in a crash on the A66 near Middlesbrough in the early hours of Saturday morning.
Here's what we know:
What we don't know:
Police watchdog the Independent Office for Police Conduct (IOPC) says it understands Cleveland Police "sighted a suspicious vehicle and a pursuit began" before the fatal crash.
In a statement, the IOPC says it is "investigating the circumstances of a fatal road traffic collision in Middlesbrough following a pursuit involving Cleveland Police officers.
It adds: "The car travelled onto the A66 in South Bank and collided with a police car at 3.39am. We can confirm that sadly multiple people have died in the collision."
The IOPC says its investigation began following a mandatory refferal from the force at 06:03 BST.
Image source, Getty ImagesReacting to the news, Redcar MP Anna Turley says her "heart goes out to every family, friend and loved one now facing the most unimaginable loss".
"Cleveland Police have confirmed that seven people have sadly lost their lives. Their families and loved ones are now facing an unimaginable loss that will be felt forever," she writes on X.
"Two of the seven people who have lost their lives were Cleveland Police officers, on duty serving our community.
"They went to work to keep people safe, and they should have come home to their families. Their loss will be felt deeply by their loved ones, fellow officers and right across the communities they served."
Turley adds that the force is now investigating the incident alongside the Independent Office for Police Conduct (IOPC).
North East Ambulance Service says it sent "14 ambulance resources" to the scene.
This included "emergency ambulance crews, a specialist paramedic, our Hazardous Area Response Team and a doctor from Great North Air Ambulance Service".
The service says it sends "condolences to all of those affected by such a tragic event" and thanks everyone for "all they did to help".
Pictures show emergency services near the site of the crash, where a police road block is in place.
Here are some of the latest images coming through:
Image source, PA Media
Image source, PA Media
The Volkswagen Passat involved in the fatal crash with a police vehicle was travelling the wrong way down the A66, according to Cleveland Police.
In a statement, the force says: "Cleveland Police can confirm that seven people have died as a result of a collision in South Bank at 3.39am this morning (Saturday 22 August).
"This includes two serving Cleveland Police officers who were in a marked police vehicle and five members of the public who were travelling in a Volkswagen Passat.
"The Passat was travelling the wrong way along the A66 and collided with a police vehicle that was travelling on the same road in the right direction.
"Sadly, all occupants of both vehicles were pronounced dead at the scene. The families of those identified have been informed and are being offered specialist support."
Here is the full statement from Cleveland Police's Chief Constable Victoria Fuller following the deaths of seven people including two police officers in a crash in Teesside:
“First and foremost, our thoughts are with the families of everyone involved in today’s incident.
“No one should leave their home and not return safely, including police officers serving their communities and protecting the people of Cleveland.
“This tragic incident will be felt across Cleveland, within our communities and throughout the entire policing family.
“We are providing specialist support to all families involved at this extremely difficult time.
“The investigation has been referred to the IOPC, which is the standard approach when a death occurs following police contact. We will cooperate fully with their investigation.
"While this investigation takes place, we strongly urge people to avoid speculation."
Two police officers have died following a collision on the A66 in South Bank, near Middlesbrough in Teesside, at about 03:39 BST, police say in a statement.
Five members of the public travelling in a Volkswagen Passat were also killed.
The Passat was travelling the wrong way along the A66 and collided with the police vehicle that was travelling on the same road in the right direction, the statement says.
We’ll bring you more on this story shortly.