Northumbria Police today made 13 arrests around the region as part of Anti-Slavery Day, which aims to tackle human trafficking.
Officers carried out search warrants at five addresses in the Cowgate area of Newcastle, and three others at Washington, Easington Lane in Houghton-le-Spring and Consett in County Durham.
Eight men and five women have been arrested - one at the Easington Lane address - on suspicion of trafficking people into the UK for exploitation, and currently remain in police custody.
Ten men and women who are believed to be the victims of exploitation were discovered during the searches and have been safeguarded by police and partners.
It is believed all those involved - victims and those who were arrested - are Polish.
Police are working with Newcastle City Council, the National Crime Agency, Crown Prosecution Service, Gangmasters Licensing Authority, British Red Cross, and Hope for Justice as part of the operation.
The raids were part of a UK-wide coordinated response to identify and arrest those responsible for human trafficking.
Detective Superintendent Steve Barron, of Northumbria Police's Safeguarding Department, said: "This is part of an intelligence-led policing response to a problem that is becoming more apparent across Europe, and it is important that we are robust in our efforts to tackle this type of crime.
"This type of crime forces people through threats or coercion to work for little or no pay, or to pay off outstanding debts.
"The activity carried out today has been a truly multi-agency effort that has focused on helping vulnerable people, and the four victims identified today have now been taken to places of safety so they can be supported by specialists from partner agencies and our officers.
"Officers are conducting reassurance patrols in the areas where the search warrants have been carried out to keep them informed about the activity in this area."
Northumbria Police and Crime Commissioner Vera Baird said: “I welcome and encourage all efforts by Northumbria Police to tackle human trafficking.
"It’s not just something that happens in other countries, it is happening right here in the North East, as these arrests demonstrate, and we must do all we can to help those caught up in such terrible circumstances.
“While there is no typical victim, those who are trafficked are mostly vulnerable, and we must all work together to identify, free and support victims and to bring the criminal traffickers and everyone involved to justice.”
Anyone with concerns about crime and human trafficking where they live should contact their local neighbourhood policing team on 101.