Cleveland Police said the incident occurred around 3:39 a.m. (0239 GMT) near the South Bank area east of Middlesbrough and that all occupants of the two vehicles died at the scene.

"This tragic incident will be felt across Cleveland, within our communities and throughout the entire policing family," Cleveland Police Chief Constable Victoria Fuller said.

The police force said it was still investigating the circumstances of the crash and was working to formally identify all the people killed.

The incident will be reviewed by Britain's Independent Office for Police Conduct, as is common practice in such cases.