Police were responding to reports of a shooting that resulted in multiple casualties, including fatalities, in Monterey Park on Saturday night, according to a law enforcement sources.

Few details were available, including the number of people shot. Internal police communications said there had been some fatalities. One law enforcement source said the causality count totaled more than a dozen people.

Seung Won Choi, who owns a seafood barbecue restaurant across the street from where the shooting happened on Garvey Avenue, said three people rushed into his restaurant and told him to lock the door.

They said there was a man with a semiautomatic gun in the area. The shooter, they said, had multiple rounds of ammunition on him, so that once his ammunition ran out he reloaded, Choi said.

Choi said he believes the shooting took place at a dance club in the area.

The shooting occurred sometime after 10 p.m. near the site of a Chinese Lunar New Year celebration. Tens of thousands had gathered Saturday for the start of a two-day festival, one of the largest Lunar New Year events in the region.

Earlier in the day, crowds were enjoying skewers and shopping for Chinese food and jewelry. Saturday’s New Year festival hours were scheduled from 10 a.m. to 9 p.m.

John, 27, who declined to give his last name, lives near the shooting site. He got home around 10 p.m. and heard about 4 or 5 gunshots, he said. Then he heard police cruisers “smashing” down the street. He went downstairs at around 11:20 p.m. to see if the shooting occurred at the New Year festival.

“My first concern was I know they’re having a Lunar New Year celebration,” he said. But he said he saw that the festival had already been cleaned up for the day when he arrived. He went to the scene of the shooting and saw one person being put on a stretcher. Another person had a bandage on their arm.

Video on social media showed police and fire units swarming an area on Garvey Avenue and treating victims.

Injured people were taken to multiple hospitals in the area.

It was unclear if a suspect was in custody.

The violence left many in the area and beyond stunned.

Edwin Chen, a 47-year-old delivery dispatcher, rushed over from Woodland Hills to Monterey Park around 12:30 a.m. after hearing the news. Chen grew up in the area and about a dozen of his family and friends live there.

He said he was saddened this happened just as the community was celebrating Lunar New Year.

“This is [supposed to be] a happy time,” he said. “I want to find out as much as possible. It’s still shocking.”

“Our hearts go out to those who lost loved ones tonight in our neighboring city, Monterey Park, where a mass shooting just occurred,” Los Angeles City Controller Kenneth Mejia, the first Asian American to hold citywide office in L.A., said in a tweet.

This is breaking news story. It will be updated as more information becomes available.