Chaos in the US House of Representatives has stretched into a second day after Republicans refused demands by Democrats, who staged a "sit-in", to bring up gun control legislation in the wake of the nation's worst mass shooting in modern history.
Scores of Democrats flooded the chamber for more than 14 hours, sitting on the floor and chanting in a "sit-in" protest, taking over the House even as the Republican leadership shut off television cameras and microphones as they tried to force lawmakers back to order.
Democrats vowed to continue their protest until Republican leaders allowed a vote on gun control legislation after the June 12 massacre in Orlando, Florida. Republicans called their move a publicity stunt.
"Mr Speaker, this is not a publicity stunt. This is a wake-up call," Democrat Mark Takano said on the House floor.
Republican House Speaker Paul Ryan refused Democrats' demands for action on gun control and instead forced a vote on an unrelated bill, even as raucous scenes spilled across the legislative chamber.
Later, the House also voted to adjourn, closing out Wednesday's "legislative" day, but planned to return at 2:30am local time to hold more votes.
During the protest, several Republican representatives charged the chamber floor and yelled at Democrats, prompting a tense confrontation that nearly descended into fisticuffs.
It was a new low for the House, which in recent years has become mired in partisanship and legislative deadlock.
"This is not a great moment for the House of Representatives," Brad Sherman, another California Democrat, said amid the melee. "Order has broken down because we have a Speaker who has not allowed us to vote."
Ryan called for decorum but could scarcely be heard over Democrats chanting "no bill, no break!" and insisting that the chamber remain in session despite a week-long break scheduled to start this weekend.
The Democrats began their protest shortly before midday on Wednesday, bringing other House business to a halt as they occupied the floor. Ryan entered the chamber about 10 hours later, and announced an immediate vote on an unrelated investment advice bill.
Democrats held up signs honouring gun violence victims during the vote.
"We will stay," House Democratic leader Nancy Pelosi said on the chamber floor as members vowed to continue their sit-in as long as it took to get a vote on a gun bill.
Ryan insisted he would not bring up any bill that would take away gun owners' constitutional rights.
Several Democratic senators crossed the Capitol on Wednesday to join protesters, including senators Elizabeth Warren, Tim Kaine and Cory Booker, all mentioned as potential running mates for presumptive Democratic presidential nominee Hillary Clinton, who voiced her support on Twitter.
Clinton's rival in the Democratic race, Senator Bernie Sanders, also appeared.
"Thank you John Lewis for leading on gun violence where we need it most," President Barack Obama tweeted.
Lawmakers also took to social media to document their demonstration with video and pictures.
Outside the Capitol, nearly 50 people gathered in solidarity at a rally organised by Everytown for Gun Safety, the advocacy group backed by former New York Mayor Michael Bloomberg.