In collaboration with the Drug Enforcement Association and the U.S. Secret Service, Oakland police said approximately 45 arrests were made during a long-term, multi-agency investigation of a gang known as "the Burn Out Family."
The gang was believed to be involved in several criminal enterprises, including drug trafficking, illegal gun possession and credit card fraud, according to police.
As many as 20 arrests were made in an acceleration of the investigation on Thursday and Friday, for charges that included narcotics offenses and fraud, police said.
Approximately 22 illegal guns have been seized during the operation, police said.
"This is another example of making large, coordinated, and meaningful impacts on the sources of violence in Oakland," Police Chief Howard Jordan said in a statement.
"We were successful through the use of our planning, covert intelligence, agency partnerships and the coordinated assistance of U.S. Attorney Melinda Haag and District Attorney Nancy O'Malley," Jordan said.
Wynn Brewer, 30, Patrick O. Shields, 29, Cyrico Robinson, 25, and Willie Howard Pope, 32, were all arrested for conspiracy to commit murder as a result of the investigation, according to police.
The investigation into the gang remains active.