A six-month investigation, called "Operation Bad Blood," targeted South Fontana, a street gang linked to the Sureños, a larger gang in Southern California.
The Sureños are affiliated with the Mexican Mafia, commonly known by its Spanish name, "La Eme" - a highly organized gang that operates from within the California prison system.
Police described La Eme as a brutal gang, involved in murders and other crimes. It is known for severely punishing disloyal members, in some cases killing them.
During the operation, officers seized illegal firearms, methamphetamine, and heroine. One of the arrested was the prime suspect in a homicide case, according to The Sun.
An additional 32 gang members targeted by Operation Bad Blood were arrested earlier on suspicion of attempted murder, assault with deadly weapon and drug trafficking, the LA Times reported.