Thirteen people were arrested this morning when police carried out a series of co-ordinated dawn raids.
Officers swooped on addresses in Lancashire, Merseyside, Cumbria and North Wales as part of an investigation into organised crime gangs and drug dealing.
More than 120 officers from Lancashire Constabulary and other North West police forces working on TITAN - a regional unit set up to help tackle serious organised crime - executed the warrants.
Warrants were carried out at 17 addresses across the region - 11 in Lancashire, three in Merseyside, two in Cumbria and one in North Wales.
The operation began at around 6am when officers, including operational support units and the dog section with drug sniffer dogs, swooped on the target addresses.
Temporary Superintendent Richard Robertshaw from Lancashire Constabulary said: "We are committed to tackling drug-related crime and we are continuing to take a firm stand against those suspected to be involved in the supply of drugs."
He added: "Information from the public has greatly assisted this operation and is vital if the police are to continue to take action against suspected criminals.
"Our work does not end here - we will continue to target those responsible for crime and disorder.
"No criminal is untouchable - with the right information we will take robust action."
All those arrested - 10 men and three women - were taken into custody to be questioned about suspected drug dealing offences.
The types of drugs involved are believed to include cocaine and cannabis.