Authorities in Southern California said nearly 500 people were arrested Halloween weekend at electronic music festivals that draw tens of thousands of people.
According to the Los Angeles Times, the arrests came amid a crackdown after two women died from apparent drug overdoses at a similar event this summer.
Police said 310 people were arrested in Pomona during the two-day HARD Day of the Dead festival at the Pomona Fairplex. The two deaths in early August occurred on the same fairgrounds on county-owned land during the HARD Summer rave.
Police arrested some 180 people during the two-day Escape: Psycho Circus rave in San Bernardino.
Most of the arrests at both events were for illegal drug possession, trespassing or public intoxication, according to the Times. Pomona police arrested nearly 100 people for having fake identification.
The Pomona event drew an estimated 20,000 people Saturday. The San Bernardino festival attracted nearly 90,000 people over two days.