Officers were dispatched to check the area of Oleander and Boyle avenues for illegal cockfighting and gambling at about 6:30 a.m.
More than 50 people fled the area on foot and in vehicles as officers arrived, according to police. Seven suspects were detained.
More than 30 dead roosters and more than 100 live roosters were found in a warehouse at the location. The live roosters were suffering from slash wounds and lacerations. A fighting ring for the roosters was found inside the warehouse. Animal Control personnel euthanized the injured birds.
Cockfighting paraphernalia was found, including razors, steroids and needles, as well as contraband and $20,000 in cash.
Juan Rodriguez, 52, of Los Angeles; Martin Velasquez, 44, of Ontario; Fred Cervantes, 37, of Baldwin Park; Oscar Galvez, 34, of Baldwin Park; Hector Hernandez, 40, of La Puente; Omar Herrera, 32, of Perris; and Ignacio Herrera, 26, of Perris were all arrested for cruelty to animals.