WASHINGTON (AP) (UPDATED) - The Pentagon says about 1,100 D.C. National Guard members were mobilized to help support law enforcement as supporters of President Donald Trump breached the U.S. Capitol.

A defense official said all 1,100 of the D.C. Guard were being activated and sent to the city’s armory. The Guard forces will be used at checkpoints and for other similar duties and could also help in the enforcement of the 6 p.m. curfew being implemented tonight in the city.

The police chief of Washington, D.C., says pro-Trump protesters deployed “chemical irritants” on police in order to break into the building.

Police Chief Robert Contee says officials have declared the scene a riot. One civilian was shot inside the Capitol on Wednesday. Thirteen arrests were made of people from out of the area.

Mayor Muriel Bowser says the behavior of the Trump supporters was “shameful, unpatriotic and above all is unlawful.” She says, “There will be law and order and this behavior will not be tolerated.”

Hoffman said the law enforcement response to the violence will be led by the Justice Department.

The exact circumstances surrounding the shooting were unclear. The person said the victim had been taken to a hospital. Their condition was not known.

BREAKING: U.S. Senate proceedings have been halted as Trump supporters attempt to storm the U.S. Capitol building; some lawmakers being escorted from the chamber. https://t.co/01SywyZ7fR

— NBC News (@NBCNews) January 6, 2021

Trump offered this tweet, after protesters entered the building:

I am asking for everyone at the U.S. Capitol to remain peaceful. No violence! Remember, WE are the Party of Law & Order – respect the Law and our great men and women in Blue. Thank you!

— Donald J. Trump (@realDonaldTrump) January 6, 2021

U.S. Rep. Elise Stefanik, R-21, who was at the Capitol Wednesday for the Electoral College certification, says she and her staff are safe.

Americans have a Constitutional right to protest & freedom of speech, but violence in any form is absolutely unacceptable & anti-American.
My staff & I are safe.

We pray that all of my colleagues on both sides of the aisle, their staff, & all Americans remain safe.

— Elise Stefanik (@EliseStefanik) January 6, 2021

Congressman Antonio Delgado, D-19, who was also at the U.S. Capitol Wednesday, said he and his staff are safe, and thanked the Capitol police for their efforts to control the situation.

My staff and I are safe. We are grateful for the brave Capitol Police officers who are doing everything they can to keep everyone safe. I’m praying for our country.

— Congressman Antonio Delgado (@repdelgado) January 6, 2021

This story is developing and will be updated.