Impeachment article has 200 cosponsors: US rep.

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.

Trump supporters were seen scaling the Capitol building steps as the proceedings continued inside. Some breached security to make it inside, to near the Senate chamber.

Senate Minority Leader Chuck Schumer lectured lawmakers in the chamber, saying an element of the GOP "believes their political viability hinges on the endorsement of an attempted coup."

"By the end of the proceedings today it will be confirmed once again something that is well-known and well-settled: the American people elected Joe Biden and Kamala Harris to be the next president and vice president of the United States," Schumer said. 

Schumer said Republicans know this fact but will object to the counting of the vote anyway -- "and in the process they will embarrass themselves, they will embarrass their party, and worst of all they will embarrass their country."

"As we speak, half of our voters are being conditioned by the outgoing president to believe that when his party loses an election, the results must not be legitimate. As we speak the eyes of the world are on this chamber questioning whether America’s still the shining example of democracy, the shining city on the hills. What message we send today, what message will we send today to our people, to the world that has so looked up to us for centuries?”

As Schumer spoke, protesters breached the perimeter outside the U.S. Capitol Building and the building went on lockdown.

A notice from United States Capitol Police to all buildings within the Capitol Complex said, "Due to an external security threat located on the West Front of the U.S. Capitol Building, no entry or exit is permitted at this time. You may move throughout the building(s) but stay away from exterior windows and doors. If you are outside, seek cover."

-ABC News' Mariam Khan, Allie Pecorin and Trish Turner