WATCH: Washington, D.C. mayor Muriel Bowser speaks about weekend shooting

WASHINGTON (AP) — A dispute that erupted into gun fire during a large outdoor party in Washington, D.C., early Sunday left one person dead and some 20 others injured, including an off-duty officer “struggling for her life,” according to police.

Watch Muriel Bowser’s news conference in the video player above.

Christopher Brown, 17, died in the shooting that occurred after midnight in a southeast side neighborhood where people had gathered for music and food, Peter Newsham, the chief of the Metropolitan Police Department, told reporters.

“There was some kind of a dispute,” Newsham said. “Multiple weapons were produced.”

Police said at least three shooters may have been involved, though no arrests were immediately announced. Newsham said a motive for the shooting wasn’t clear.

Fellow officers took the injured off-duty officer to a local hospital.

“She’s struggling for her life right now,” he said. He added that “the rest of the gunshot wounds, as far as we know, are non-life-threatening.”

Nelson Bostic, a resident in the area, told WTOP he heard a burst of rapid gunfire, then saw “people laying on the ground” and “ducking under cars.”

“It was terrible,” he said.

Relatives of the teenager killed described him as someone who was full of energy and quick to smile. He also had a 1-year-old son.

“A lot of people know him as just a good person,” his mother, Artecka Brown, told WUSA9. “That was an innocent life taken for no reason.”

There may have been hundreds of attendees at the party despite city restrictions during the coronavirus pandemic on such large gatherings.

“We can’t tolerate these types of gatherings in our city during COVID-19,” Newsham said. “It’s just too dangerous.”

Mayor Muriel Bowser, speaking to reporters near the scene of the shooting, noted that public drinking and marijuana use outside were prohibited, as were gatherings of more than 50 people as a precaution against spreading the coronavirus.

“It’s very important that as a community we have a zero-tolerance for this activity,” she said. Bowser added that police will have to make some “difficult decisions” and “break up these events.”

The gathering had been advertised on fliers as the “34th-n-EAT” cookout that would start late Saturday, The Washington Post reported. It would, the flier added, be a “drama free event.”