WASHINGTON (Reuters) -Hundreds of President Donald Trump’s supporters stormed the U.S. Capitol on Wednesday in a stunning bid to overturn his election defeat, occupying the symbol of American democracy and forcing Congress to suspend a session to certify President-elect Joe Biden’s victory.

Rioters forced their way past metal security barricades, broke windows and scaled walls to fight their way into the Capitol, where they roamed the hallways and scuffled with police officers.

Some besieged the House of Representatives chamber while lawmakers were inside, banging on its doors. Security officers piled furniture against the chamber’s door and drew their pistols before helping lawmakers escape. [L1N2JI04K]

Police struggled for more than three hours after the invasion to clear the Capitol of Trump supporters before declaring the building secure shortly after 5:30 p.m. (2230 GMT).

One woman died after being shot during the mayhem, Washington police said, although the victim was not named and the circumstances were unclear. The FBI said it had disarmed two suspected explosive devices.

The assault on the Capitol was the culmination of months of divisive and escalating rhetoric around the Nov. 3 election, with Trump repeatedly making false claims that the vote was rigged and urging his supporters to help him overturn his loss.

The chaotic scenes unfolded after Trump - who before the election refused to commit to a peaceful transfer of power if he lost - addressed thousands of supporters near the White House and told them to march on the Capitol to express their anger at the voting process.

He told his supporters to pressure their elected officials to reject the results, urging them “to fight.”

Trump came under intensive fire from some prominent Republicans in Congress, who put the blame for the day’s violence squarely on his shoulders.

“There is no question that the President formed the mob, the President incited the mob, the President addressed the mob. He lit the flame,” House Republican Conference Chairwoman Liz Cheney said on Twitter.

Republican Senator Tom Cotton, a leading conservative from Arkansas, called on Trump to accept his election loss and “quit misleading the American people and repudiate mob violence.”

A source familiar with the situation said there have been discussions among some Cabinet members and Trump allies about invoking the 25th Amendment, which would allow the majority of the Cabinet to declare Trump unable to perform his duties and remove him. A second source familiar with the effort doubted it would go anywhere with Trump having just two more weeks in office.

Both houses of Congress resumed their debate on the certification of Biden’s Electoral College win on Wednesday evening.

It quickly became clear that objections from pro-Trump lawmakers to Biden’s victory in battleground states would be rejected overwhelmingly, including by most Republicans, and that the election results would be certified.

“To those who wreaked havoc in our Capitol today - you did not win,” Vice President Mike Pence, who presided over the session, said as it resumed. “Let’s get back to work,” he said, drawing applause.

Senate Republican leader Mitch McConnell, who has remained silent while Trump has sought to overturn the election result, called the invasion a “failed insurrection” and promised that “we will not bow to lawlessness or intimidation.”

“We are back in our posts. We will discharge our duty under the Constitution, and for our nation. And we are going to do it tonight,” he said.

‘RECKLESS BEHAVIOR’

After lawmakers resumed debate on the last-ditch effort to overturn the election results, it was not clear how late into the night the sessions would go.

The Senate rejected by a 93-6 vote Republican objections to the certification of Biden’s victory in the battleground state of Arizona, ensuring their defeat. The House of Representatives, controlled by Democrats, was still debating the Arizona objections, but a majority of both chambers would need to approve it.

Republican Senator Kelly Loeffler, who lost her re-election bid in one of two Georgia runoffs on Tuesday that secured Democratic control of the Senate, said she had planned to object to Biden’s certification but had changed her mind after the events of the afternoon.

“I cannot now in good conscience object to the certification of these electors,” she said.

Washington Mayor Muriel Bowser ordered a citywide curfew starting at 6 p.m. (2300 GMT). National Guard troops, FBI agents and U.S. Secret Service were deployed to help overwhelmed Capitol police. Guard troops and police pushed protesters away from the Capitol after the curfew took effect.

It was the most damaging attack on the iconic building since the British army burned it in 1814, according to the U.S. Capitol Historical Society.

Biden, a Democrat who defeated the Republican president in the November election and is due to take office on Jan. 20, said the activity of the protesters “borders on sedition.”

The former vice president said that for demonstrators to storm the Capitol, smash windows, occupy offices, invade Congress and threaten the safety of duly elected officials: “It’s not a protest, it’s insurrection.”

TRUMP REPEATS FALSE CLAIMS

In a video posted to Twitter while the rioters roamed the Capitol, Trump repeated his false claims about election fraud but urged the protesters to leave.

“You have to go home now, we have to have peace,” he said, adding: “We love you. You’re very special.”

Twitter Inc later restricted users from retweeting Trump’s video, and Facebook Inc took it down entirely, citing the risk of violence. Twitter said later it had locked the account of Trump for 12 hours over “repeated and severe violations” of the social media platform’s “civic integrity” rules and threatened permanent suspension.

Election officials of both parties and independent observers have said there was no significant fraud in the Nov. 3 contest, in which Biden won 7 million more votes than Trump.

Weeks have passed since the states completed certifying that Biden won in the Electoral College, which decides presidential elections, by a 306-232 vote. Trump’s extraordinary challenges to Biden’s victory have been rejected by courts across the country.

Trump had pressed Pence to throw out election results in states the president narrowly lost, although Pence has no authority to do so. Pence said in a statement he could not accept or reject electoral votes unilaterally.

The mayhem stunned world leaders. “Trump and his supporters must accept the decision of American voters at last and stop trampling on democracy,” German Foreign Minister Heiko Maas said.

Business groups, normally staunch allies of Republicans in Washington, also reacted strongly. The National Association of Manufacturers said Pence should consider invoking a clause in the Constitution that allows a president to be removed from office when he is unable to do his job.

“This is sedition and should be treated as such,” said the group’s president, Jay Timmons.