Impeachment article has 200 cosponsors: US rep.

There’s been an armed standoff at the front door of the House of Representatives and security officers drew their guns drawn at someone who is trying to breach the door, according to a pool reporter in the House chamber.

Another pool reporter on Capitol Hill said he observed protestors breach the Senate chamber. Senators were evacuated earlier, per sources.

One man stood up on the Senate dais and said, "Trump won that election," according to the pool reporter, who also observed protests stalking the halls, appearing to look for senators.

Several dozen protesters were heard yelling, "Where are they?"

Capitol Police were asking for additional law enforcement assistance as protests intensify.

-ABC News' Trish Turner

Lawmakers were being evacuated rom the House floor after protesters began banging on door, according to a pool reporter in the House gallery.

Moments earlier, an officer told lawmakers they may need to duck under their chairs as protests escalated inside of the building.

"We now have individuals that have breached the Capitol building. They are in the Rotunda area," the dispatch said.

Lawmakers still in the gallery were told to "be prepared" to relocate to cloakrooms.

Rep. Steve Cohen, D-Tenn., screamed from the gallery, "Call Trump! Call your friend!"

Rep. Jim Himes, D-Conn., tweeted, "Police have asked us to get gas masks out as there has been tear gas used in the Rotunda."

Trump finally broke his silence, after about an hour of protests, but did not call for the protesters to go home but to "Stay peaceful!"

Sen. Chuck Grassley interrupted the proceedings, taking over for Vice President Mike Pence to preside over the Senate -- calling the Senate into recess subject to the call of the chair as protesters breached the inside of the U.S. Capitol building.

Pence appeared to have been moved out of the Senate chamber. The House of Representatives was being evacuated.

As protesters of the Electoral College count and supporters of the president breached the Capitol building, Trump did not call for calm but attacked Vice President Mike Pence on Twitter.

"Mike Pence didn’t have the courage to do what should have been done to protect our Country and our Constitution, giving States a chance to certify a corrected set of facts, not the fraudulent or inaccurate ones which they were asked to previously certify. USA demands the truth!" Trump tweeted.