Five young men who died after their vehicle hit a police car on a dual carriageway may have had links to “serious and organised criminal activity”, police said.
Cleveland Police said 12 other people have been arrested over alleged criminality leading up to the collision in Teesside in which seven people, including two police officers, were killed.
These included four people arrested on suspicion of participating in an organised crime group and four on suspicion of possessing a firearm.
Four of the suspects are also accused of possessing Class A and B drugs with intent to supply.
Four of the five young men in the car had previous criminal convictions, and were believed to be associated with another car which was seen ramming properties earlier that morning.
Pc Matthew Blades, 37, and Pc Tom Clough, 38, were killed when a Volkswagen Passat – which had been pursued by police – was driven the wrong way along a dual carriageway near Middlesbrough and hit their marked armed response vehicle.
The five people travelling in the Volkswagen – Cole Robert Worthy, 17, Theo Rae, 17, Makai Saddington, 18, and 23-year-olds Michael Robert Cahill and Jacob Matusiak – were pronounced dead at the scene at South Bank, early on Saturday.
Police said nine men and three women, aged between 19 and 61, have been arrested after an investigation over the weekend into alleged criminal activity before the crash.
The force said on the morning of the collision, it received several reports of two vehicles being driven dangerously.
The first vehicle, believed to be a Volvo XC60, was witnessed ramming properties in the Middlesbrough area.
The second vehicle, a Volkswagen Passat, is believed to have been associated with the activities of the Volvo.
Police said both vehicles were operating with cloned number plates but were picked up by automated number plate recognition technology.
The Volvo XC60 involved in the initial reports has been traced and recovered in Middlesbrough.
Police said there was no evidence that filming of the activities on Friday night and Saturday morning was “for the purposes of TikTok”.
Twelve people arrested in connection with crash that killed two police officers