A further four people have been arrested afte police raids took place in Newcastle at dawn as part of an investigation by Northumbria Police.
The total of people who have now been arrested during Operation Magnet now stands at 14.
12 men have been arrested on suspicion of conspiracy to supply controlled drugs, and two women have been arrested on suspicion of attempting to conceal criminal property.
They are all currently in police custody.
"Fifteen addresses were visited today and 14 people have so far been arrested. This was clearly a crime group working together and this operation has significantly disrupted that group's activities.
"I would like to thank our local communities who supply us with information and tell us what is happening in their local area. It means activity like this can take place. This is what we do with that information and how seriously we take it.
"Operation Magnet will continue and Northumbria Police's message to anyone who is involved in the supply of drugs or organised crime is simple - once we find out who you are you can expect a similar visit by police."
More top news
There has been 14 cases of drug related overdoses in the last 24 hours, one of which resulted in the death of a 50-year-old man.
Balloons were released for teenage couple Chloe Rutherford and Liam Curry, while flowers have been laid for Philip Tron and Courtney Boyle.
33-year-old Shaun O'Connell, who lived in Throckley, died after a two vehicle collision on the A696 near Kirkwhelpington near Otterburn.