A Metropolitan Police Department report describes a violent incident near Audi Field after Sunday’s D.C. United Game, which reportedly involved Washington fans and West Coast-based supporters of the Seattle Sounders.

According to the police report, seven people were leaving Audi Field when a dozen D.C. United fans “began physically harassing them” through pushing, kicking, and punching. The suspects fled on foot in the 1800 block of Half Street SW, per the report.

Emerald City Supporter, a Seattle Sounders fan group, said on Twitter that its members were the victims, and that the group was assisting the Sounders and Major League Soccer “in identifying the cowards who perpetrated this unprovoked attack.”

On Monday afternoon, D.C. United released a statement saying the team was “deeply concerned about this incident.” The statement notes that the team “held the away supporter group for 20 minutes after the final whistle, per league protocol, and the supporters were then escorted outside the stadium.” D.C. United is culling its security footage and working with the city to find any other available footage, per the statement. “Fan safety is our top priority and we are committed to eradicating any violence in our around the stadium,” the statement reads.

According to Sounders blog Sounder at Heart, while Audi Field security held Emerald City Supporter fans in the designated supporters section as required, the traveling fans did not receive any security escort outside of the stadium. Security told witnesses, “Our jurisdiction ends at the gate,” reports Sounder at Heart.

That’s when alleged D.C. United supporters approached Seattle fans and tried to grab the equipment they used to wave flags, per Sounder at Heart. The police report outlines injuries like scrapes, scratches, and cuts, as well as severe pain and swelling in one victim’s jaw. According to Sounder at Heart, one of the fans was hospitalized in stable condition.

One of D.C. United’s longtime fan groups, Barra Brava, sent a statement to DCist: “First and foremost our thoughts are with the Sounders Fan(s) who were attacked last night. We hope they have a speedy recovery. Immediately, after learning of the incident via twitter we contacted the DC United Front Office to express our disgust and offer any assistance we can to bring those responsible for justice. Violence is not tolerated in the Barra Brava and has no place in the sport we all love.
We have no information as to who is responsible. I wish that we did so that the perpetrators can be held accountable.” The statement goes on to say that the group is asking for anyone with information or footage of the incident to get in touch so they can assist in finding the culprits.

“Contrary to social media reports we have no knowledge about any previous incidents and none has been ever brought to our attention by the either the Front Office or anyone else,” the statement reads. “Barra Brava has always rejected violence and our track record over many years backs this up.”

This story has been updated with a statement from Barra Brava.