A murder investigation has been launched after a house fire in Middlesbrough killed two people, with police not ruling out links to organised crime.

The blaze in the early hours of Wednesday came as police continued to investigate the wider circumstances around a collision on Saturday on the A66 that killed seven people, including two police officers.

Cleveland police said officers were called at 5.23am to reports of a house fire in the Grangetown area of Middlesbrough.

Two people died in the fire and a woman was in hospital in Newcastle in a critical condition, police said. A further three people sustained non-life-threatening injuries and were receiving treatment in hospital, a spokesperson added.

Supt Emily Harrison, Redcar and Cleveland’s local policing commander, said: “We are working to establish the circumstances of exactly what has happened, but we are keeping an open mind and cannot rule out any links to wider organised crime at this time.”

The blaze was about two miles from the scene of Saturday’s collision in which a Volkswagen Passat, travelling in the wrong direction, crashed head-on into a police vehicle on the A66. PC Matthew Blades, 37, and PC Tom Clough, 38, were killed in the collision.

The five occupants of the Volkswagen Passat were also killed, and pronounced dead at the scene. They have been named as Cole Worthy and Theo Rae, both 17, Makai Saddington, 18, and Michael Robert Cahill and Jacob Matusiak, both 23.

Since then Cleveland police said they had “continued to disrupt those suspected of being involved in serious and organised crime”. That effort has resulted in 17 arrests.

Wayne Fox, the assistant chief constable responsible for the strategic leadership of the investigation, said: “This has been a fast-moving and complex investigation, with significant links to serious and organised criminal activity. The events of that tragic night will have a lasting and profound impact on the Cleveland area and the communities we seek to protect.

“We have a duty to respond to, and thoroughly investigate, the serious criminal activity that resulted in this fatal incident, and to bring all those responsible to justice. Our robust response will continue in the weeks and months to come, as we continue to tackle those that seek to cause harm to our communities and tackle serious and organised crime.”

Cleveland fire brigade said it had sent six fire engines and an incident command unit to the scene of the Grangetown blaze. A spokesperson said road closures were in place in the surrounding area and asked members of the public to avoid the area where possible.

Adam Brook, a Redcar and Cleveland borough councillor for Grangetown, said the fire was “absolutely devastating”, but urged people not to speculate or “share unconfirmed information”. He said: “Many residents have been in touch with me throughout the morning, and I know there is understandably a great deal of concern. However, I would urge people not to speculate or share unconfirmed information.”