D.C. Mayor Muriel Bowser ordered a curfew of 6 p.m. ET in the nation’s capital, saying of the violent mobs that overtook the U.S. Capitol Building, “there will be law and order and this behavior will not be tolerated.”

Police Chief Robert Contee announced at a news conference that they’re treating the scene as a riot. Police have arrested 13 inside the Capitol, and several people were taken to the hospital, including one person who was shot.

Bowser added that extremists deployed “chemical irritants” on police officers to gain entry into the building.

Authorities from neighboring states, including New Jersey, Virginia, and Maryland, are being deployed to assist city law enforcement.

Bowser called the behavior “shameful, unpatriotic and above all … unlawful.”