At least nine people were killed in a mass shooting late Saturday in a city east of Los Angeles following a Lunar New Year celebration that attracted thousands, police said.

Sgt. Bob Boese of the Los Angeles County Sheriff’s Department said the shooting was reported at 10:22 p.m. and occurred at a business on Garvey Ave. in Monterey Park. The shooter is a male, Boese said early Sunday.

 It was unclear if the suspect was in custody.

Officials provided no information for several hours after dozens of police officers had responded to reports of the shooting.

Monterey Park is a city of about 60,000 people with a large Asian population that’s about 10 miles from downtown Los Angeles.

Saturday was the start of the two-day festival, which is one of the largest Lunar New Year events in Southern California. Earlier in the day, thousands of people attended the annual festival.

One neighbor told CBS Los Angeles the gunshots sounded like fireworks, but due to the celebrations in the area, he did not think much of it at the time. 

Seung Won Choi, the owner of a nearby seafood restaurant, told the Los Angeles Times that three people rushed into his restaurant. The people, he said, said there was a gunman with a semiautomatic gun who had reloaded after opening fire.

This is a breaking news story. Please check back for updates.