Police released a preliminary arrest total around 4:30 p.m., and said they would provide another update Sunday.
The arrests include four firearms violations, two simple assault, one no permit, one assault of a police officer and two disorderly conduct.
Police warned against taking guns to rallies.
“We see some folks that are communicating on social media suggesting that they’re going to bring firearms into our city,” D.C. Police Chief Peter Newsham said. “You cannot open carry in the District of Columbia, anywhere in the District of Columbia.”
In D.C., firearms can only be carried with a district-authorized concealed carry permit, and even then they are banned from public demonstrations.
Thousands descended on D.C. to support the president’s election battles as he fights results that favor President-elect Joe Biden. Anti-Trump and Black Lives Matter protesters joined the crowd as well, leading to a few violent faceoffs.
Within an hour of the event’s kickoff, Trump and Biden supporters could be seen shoving each other.
One man who was seen in the clip facing off with a Trump supporter appeared with a bloody face on camera. NBC News4 said he was assaulted by a member of the Proud Boys, a far-right group.
Video shows “MAGA” flags being burned and one anti-Trump demonstrator ripping an American flag out of a man’s hand.
Another video shows a man with a bloody head, stumbling before falling to the ground. Twitter user Brendan Gutenschwager, who shot the clip, said the man, a Trump supporter, was assaulted before D.C. police came in.
In another of Gutenshwager’s clips, a protester can be seen rushing up behind a woman to punch her in the head before running off. She reportedly was a Trump supporter.
Earlier in the day, the president and his motorcade drove past the supporters, some of them waving Trump flags and holding signs saying “Stop the Fraud” and “Best Prez Ever.” The crowd chanted “Four More Years!” as Trump gave a thumbs up.
Enthusiastic Trump supporters delivered a series of fiery speeches from Freedom Plaza repeating Trump’s unfounded claim of widespread election fraud and that Trump actually won. Some talked of more specific ways to stop Biden from becoming president, including legal challenges, election audits and urging states to appoint pro-Trump electors who would defy the popular vote results in their states.
“This election was stolen from us,” said Courtney Holland, a conservative activist from Nevada, told the crowd, a line that was often repeated. She then led a chant of “Stop the Steal!”
Speeches were also expected from Rep. Mike Kelly, R-Penn.; Rep. Paul Gosar, R-Ariz.; Rep.-elect Marjorie Taylor Greene, R-Ga.; Rep. Louis Gohmert, R-Texas, and others.