"This incident is currently under investigation," a police spokeswoman told BuzzFeed News on Tuesday.
The video — which was widely shared by conservative and right-wing bloggers — has had more than 950,000 views on YouTube since it was posted on Jan. 20.
According to a police report provided to BuzzFeed News, the victim alleged that her hair was set on fire during a protest near the National Archives Building located north of the National Mall. She did not sustain any injuries, the report said.
The report was filed by Becky O'Neil, a woman from Arlington, Virginia.
When reached by phone on Tuesday, O'Neil told BuzzFeed News that the alleged victim was her 17-year-old daughter, who she asked not be named for this story.
"She's fine," O'Neil said.
O'Neil said the incident happened near the National Mall while her daughter was on the way to the inauguration parade on Saturday.
When asked if she believed that an anti-Trump protester set her daughter's hair on fire, O'Neil said, "That's what it appears to be in the video."
O'Neil said that she wasn't present when the alleged incident took place, adding, "All I know is what I saw on social media."
She said she and her daughter were waiting to speak to the police before providing any more details.