Armed police raided nine houses and arrested 13 people in Leeds on Thursday morning after receiving a tip-off.
The addresses in the Chapeltown and Harehills areas of the city were targeted as part of an ongoing anti-drug and gun crime initiative by West Yorkshire police.
Those detained were being questioned about a number of offences, including possession of offensive weapons and drugs, although one person is being questioned about an alleged kidnap and blackmail.
Police say a substance, thought to be crack cocaine, and a number of weapons were recovered during the raids and forensic experts are conducting examinations of the items.
Chief Supt Dick Rothwell, who was in charge of the operation, said he was satisfied with the way the operation went.
He said: "The houses were all entered at the same time to recover drugs...and stolen property along with other items relating to criminal activity."
And he revealed that police acted after receiving information from members of the public.
He added: "The public in Chapeltown and Harehills are absolutely sick to death of people dealing on the streets, and they are sick to death of people who use, and are involved with guns."