A photo shot and tweeted from the floor of the House by US House Rep David Cicilline shows Democratic members of the US House of Representatives, including Rep John Lewis (right) staging a sit-in on the House floor "to demand action on common sense gun legislation" on Capitol Hill in Washington, US, June 22, 2016. [Photo/Agencies]

Rebellious Democrats shut down the House's legislative work on Wednesday, staging a sit-in on the House floor and refusing to leave until they secured a vote on gun control measures before lawmakers' weeklong break.

Exasperated Republicans were forced to recess while cutting off cameras that showed the protest. But in an unprecedented step, C-SPAN used live video feeds from one lawmaker's Periscope account and another's Facebook page to transmit words and images from the House chamber.

More than 200 Democrats led by Georgia Rep John Lewis demanded a vote on measures to expand background checks and block gun purchases by some suspected terrorists in the aftermath of last week's massacre in Orlando, Florida, that killed 49 people in a gay nightclub.

"No bill, no break," shouted Democrats, who demanded that Speaker Paul Ryan keep the House in session through its planned break next week to vote on gun legislation.

Democrats accused Republicans of political cowardice by failing to schedule a vote.

"Are they more afraid than the children at Sandy Hook?" asked Rep Mike Thompson, referring to the 2012 shooting that killed 26 people, including 20 elementary school children, in Newtown, Connecticut. "What is so scary about having a vote?"

Lewis, a veteran civil rights leader, asked what Congress has done, then answered his own question: "Nothing. We have turned a deaf ear to the blood of innocents. We are blind to a crisis. Where is our courage?"

Rep Frank Pallone called Republicans "cowards."

Ryan dismissed the protest as "nothing more than a publicity stunt." In an interview with CNN, the Speaker said the House will not vote on a "bill that takes away a person's due process."

Republicans emerging from a closed-door meeting said they would hold votes on other legislation, but not the gun votes demanded by the Democrats.

"We are going to go about our business starting tonight," said Republican Rep Ann Wagner. Democrats were certain to challenge any move.