A 17-year-old boy is dead and 20 others wounded following a shooting at what appeared to be a street party in a southeast Washington, D.C., neighborhood early Sunday, authorities said.

Police were called to the scene around 12:30 a.m. after multiple shooters opened fire into a crowd of people. An off-duty police officer was among those most seriously wounded in the attack, police said.

Shes struggling for her life right now at a local hospital, Metropolitan Police Chief Peter Newsham said at a news conference.

No arrests had been made as of late Sunday morning, he said.

Newsham described the scene leading up to the violence as some kind of a social gathering.

There was some kind of dispute, and multiple weapons were produced, and multiple shots were fired, he said, describing the shooting as an isolated incident.

Hundreds of people packed the street for the social event, a neighbor told WUSA9.

The mass gathering violated current health protocols in place because of the ongoing coronavirus pandemic, Washington Mayor Muriel Bowser said at a morning news conference.

Its very important that as a community we have a zero-tolerance for this activity, she said. She also condemned the use of alcohol and marijuana on public streets.

We had a lot of people who were in a dangerous situation last night, and, sadly, several people who had no regard for human life opened fire at what had been, it looked like, people together enjoying themselves, she added.