The venue, a gathering place for ballroom dancers, drew big crowds on Saturday nights.

MONTEREY PARK, Calif. — Located on a busy commercial street among grocery stores and Chinese restaurants, the Star Ballroom Dance Studio in Monterey Park is a popular gathering place for lovers of ballroom dancing in the Los Angeles area, and promises to train attendees in anything from the tango to the fox trot.

“That place is always packed, man,” said Alejandro Delatorre, 40, a dance instructor who worked at the venue last year and arrived early Sunday, after 10 people were killed and 10 others injured in a late-night shooting. He said that more than 90 percent of Star Dance’s clientele was Asian American.

Saturday nights drew large crowds, filling the floor with ballroom dancers of all ages. The playlist often included songs in Chinese, said Walter Calderon, 47, a dance teacher in Orange County. “It’s a huge dance floor — 6,000 square feet, with a huge amount of parking,” he said. “Most of the dancers go there.” The venue posts its schedule online in English and Chinese.

When the Monterey Park police reached the scene on Saturday night, dozens of people were streaming out of the venue, some of them with injuries, the authorities said. In all, five women and five men died in the shooting, and at least 10 more were injured, some critically.

Mr. Calderon said the dance venue would have been especially full on Saturday, the eve of Lunar New Year. “There would have been hundreds and hundreds of people there,” he said.

The Los Angeles County Sheriff’s Department said it believed the shooting at Star was connected to an incident in nearby Alhambra that occurred about 20 minutes after the Monterey Park shooting. The department said people at a dance venue there wrestled a firearm away from a man who then fled the scene. Local media identified that venue as the Lai Lai Ballroom & Studio.

On Sunday morning, a woman arrived at the Lai Lai, entered the building using a key code, and put up a sign saying the studio was closed “in observance to the Star Dance tragedy.” She said nothing to two reporters who were present as she got in her car and drove away.

In Monterey Park, the area of Garvey Street outside Star Dance remained blocked off by law enforcement on Sunday morning. Signs of the Lunar New Year celebration that had taken place the day before were still apparent, including a small temporary stage and a red banner reading: “Happy Year of the Rabbit!”