Suspected drug dealers and serious organised criminals are being targeted in Calderdale following a six-month evidence-gathering operation.
Since Monday, when the arrest phase of the operation began, 43 people have been arrested from across the district, including in Halifax and Todmorden.
Police have spent months investigating drug dealers as well as those suspected of being involved in the supply of guns.
The arrests follow six months of investigation using police intelligence and information passed to police by members of the public.
A significant quantity of drugs and cash and a large amount of counterfeit goods have also been seized during the police raids.
Superintendent Stan Bates, head of operations for Calderdale, said: "Calderdale CID and officers from the force's crime division have used a wide range of pro-active and conventional policing techniques to gather evidence of criminals involved in crime and drug dealing in Calderdale.
"In the last six months police have amassed sufficient evidence to arrest and charge people who are involved in criminal activity and who cause the most harm in our communities.
"This is a major operation against people who have no consideration for the lives they are ruining through their drug dealing and criminal activity.
"The nature and scale of this operation demonstrates our ongoing commitment to targeting criminals in Calderdale who think they can get away with preying on law-abiding people.
"I hope this sends out a clear message to all criminals that we will not standby and allow people to live off the proceeds of their crimes."
Detective Inspector Ian Devey, of the Force's organised crime group, said: "The lead-up to this week's arrests has seen officers carrying out intensive investigations to gather intelligence on people suspected of being involved in burglary and other serious offences, including the supply of drugs and firearms."