VAL VERDE, Calif. (AP) — Some 7,000 birds were seized in one of the largest raids of illegal cockfighting in United States history, authorities said Tuesday.

About 100 Los Angeles County sheriff's deputies conducted the raid on Monday, seizing roosters, hens and chicks in a remote area northwest of Los Angeles, authorities said at a news conference.

Injured and dead roosters also were found, along with mobile cockfighting pits, slashing blades used during fights to the death and other equipment, officials said.

The birds, goats and about 50 guard dogs were turned over to county animal control officials.

Two handguns also were seized, authorities said.

"This was a breeding operation and also a place where the fights took place," sheriff's Sgt. Bob Boese told the Santa Clarita Valley Signal (http://bit.ly/2qOptSY).

About 10 people were detained, including the property owners and others working on the property, Boese said.

Arrests will be made after detectives and prosecutors determine which specific laws were broken, he said.

Although it is illegal, cockfighting remains a popular and lucrative betting sport, authorities said.

In 2007, authorities seized 2,700 birds during a raid on the same property.

Last November, nearly a dozen people were detained and several roosters were rescued after authorities busted a weekend cockfighting tournament at a Santa Clarita farm, where spectators bet thousands of dollars, officials said.