A protester made his way inside the U.S. Capitol building on Tuesday afternoon and threw Russian flags at President Trump before being detained by authorities.

The man, who identified himself as Ryan Clayton from the group Americans Take Action, shouted that "Trump is treason."

The president was walking with Majority Leader Mitch McConnell heading for a lunch with Republican senators.

As the pair walked past members of the press, Clayton lobbed a handful of Russian flags emblazoned with the word "Trump."

"We should be talking about treason in Congress, not about tax reform," he shouted as authorities took him away.

It's unclear how the activist managed to get in the press area and within a few feet of the president, despite tight security at the Capitol because of Trump's visit.