Officers carried out drugs warrants and arrested outstanding suspects.
Police have launched a series of early morning raids as part of a crackdown on drug dealing and organised crime around Middlesbrough.
The area has seen increased police activity since a crash on the A66 killed two officers and five young men on August 22.
On Monday Cleveland Police raided properties in Redcar and the South Bank and Grangetown areas of Middlesbrough as part of Operation Artemis.
Officers carried out drugs warrants and arrested outstanding suspects.
On Monday afternoon the force said they had carried out four warrants and made 17 arrests for offences including drug supply and theft of a motor vehicle.
Seizures included suspected class A and class C drugs, cash, a knife, knuckle duster, a baton, an illegal e-bike, an electric scooter, an electric assisted pedal cycle or “revvi” and a suspected stolen wacker plate construction tool.
Police said officers made four arrests at one address in Birchington Avenue, Grangetown, on suspicion of drugs supply offences.
Three men, aged 37, 43 and 60, and a 58-year-old woman were taken into police custody.
An amount of suspected class A drugs was recovered along with a quantity of cash, and a dog which was believed to be a banned breed was seized.
At another address in Moorbeck Way, Ormesby, officers recovered a knife, a baton and a knuckle duster, and recovered suspected class C drugs.
Pc Matthew Blades, 37, and Pc Tom Clough, 38, were killed when a Volkswagen Passat going the wrong way along the A66 dual carriageway hit their marked armed response vehicle on August 22.
The five young men in the Passat were also killed.
