A dispute that erupted into gun fire at an apparent outdoor party in Washington, D.C., early Sunday left one person dead and some 20 others injured, including an off-duty officers “struggling for her life,” according to police.

A 17-year-old male died in the shooting that occurred after midnight in a southeast side neighbourhood 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.” He said a motive for the shooting wasn’t clear.

The off-duty officer was taken by fellow officers to a local hospital, Newsham said.

“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.”

No arrests were immediately announced.

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

Nelson Bostic, a resident in the area, told WTOP the gathering appeared to be a birthday party. After the burst of gunfire, he said he saw “people laying on the ground” and “ducking under cars.”

“It was terrible,” he said.