Protesters supporting President Donald Trump stormed the U.S. Capitol Wednesday, clashing with police and forcing a delay in the constitutional process to affirm President-elect Joe Biden’s win.

Dozens of people breached security perimeters at the Capitol and lawmakers inside the House chamber were told to put on gas masks as tear gas was fired in the Rotunda.

A chaplain prayed as police guarded the doors to the chamber and lawmakers tried to gather information about what was happening, and an announcement was played inside the Capitol as lawmakers were meeting and expected to vote to affirm Biden’s victory. Due to an “external security threat,” no one could enter or exit the Capitol complex, the recording said.

Protesters were also seen inside the Senate chamber. One got up on the dais and yelled “Trump won that election.”

Several dozen are roaming through the halls, yelling “Where are they?” according to a pool report.

Congressional leaders were whisked to safety. Vice-President elect Kamala Harris, who was attending the joint session, was also said to be safe.

At an earlier rally, Trump had urged his supporters to march to the Capitol. After protesters clashed with law enforcement and breached the Capitol building, Trump tweeted to his supporters to “stay peaceful.”

“Please support our Capitol Police and Law Enforcement,” Trump tweeted, as tear gas was deployed in the locked-down Capitol. “They are truly on the side of our Country. Stay peaceful!”

“We’re going to cheer on our brave senators and congressmen and women, and we’re probably not going to be cheering so much for some of them,” Trump said.

Both chambers abruptly went into recess. The District of Columbia’s mayor, Muriel Bowser, issued a curfew for 6 p.m.

The skirmishes occurred outside in the very spot where President-elect Biden will be inaugurated in just two weeks.

Protesters tore down metal barricades at the bottom of the Capitol’s steps and were met by officers in riot gear. Some tried to push past the officers who held shields, and officers could be seen firing pepper spray into the crowd to keep them back. Some in the crowd were shouting “traitors” as officers tried to keep them back.

A suspicious package was also reported in the area, Capitol Police said.

The skirmishes came just shortly after Trump addressed thousands of his supporters, riling up the crowd with his baseless claims of election fraud at a rally near the White House on Wednesday ahead of Congress’ vote.

“We will not let them silence your voices,” Trump told the protesters, who had lined up before sunrise to get a prime position to hear the president.