Democrats prayed and sang Christian civil rights anthem "We Shall Overcome" while staging a sit-in on the floor of the US House of Representatives to demand action on gun control in America.

Republicans voted early Thursday morning to adjourn the House until after the July 4 recess to try and stop the 16-hour sit-in staged by the Democrats seeking a vote on gun control measures in the aftermath of the Orlando massacre.

The sit-in, which began at 11:29am on Wednesday and involved more than 100 House Democrats, was led by veteran civil rights campaigner Rep John Lewis. They continued to give speeches after the adjournment vote.

It continued throughout the night with banners waved and chants sung, drowning out Speaker Paul Ryan. Democrats sat in the "well" and read out the names of the 49 killed in Orlando.

"Mr Speaker, give us a vote!" shouted one protester.

Lewis, 76, who was a leader in the civil rights movement and took part in sit-ins during the struggle, told the House: "We have been quiet for too long. There comes a time when you have to say something. You have to make a little noise. You have to move your feet. This is the time.

"How many more mothers? How many more fathers need to shed tears of grief before we do something? Give us a vote. Let us vote. We came here to do our job. We came here to work."

Republicans called a recess for the House and shut off microphones and cameras, however recordings of the protest went public.

President Barack Obama wrote on Twitter: "Thank you John Lewis for leading on gun violence where we need it most."

Hillary Clinton tweeted: "This is what real leadership looks like".

House Speaker Paul Ryan's spokeswoman AshLee Strong said in a statement: "Democrats can continue to talk, but the reality is that they have no end-game strategy.

"The Senate has already defeated the measure they're calling for. The House is focussed on eliminating terrorists, not constitutional rights of law-abiding citizens. And no stunts on the floor will change that," she added.

Addressing fellow Democrats, Lewis said: "Thank you for getting in trouble – good trouble. Yes to trouble!

"I never, ever thought that one day, after sitting in here many days and many nights, that one day I would be more than lucky but very blessed... to sit down on the House floor with all you great ladies and gentlemen.

"We have a right to protest for what is right. That's all we can do. There are people hurting, there are people suffering, so we have an obligation, a mandate, to do something.

"Maybe our forefathers all came to this land in different ships," Lewis said, "but we're all in the same boat now."

The sit-in was broadcast via Periscope on the phone of Democrat Scott Peters, continuing the recording after the official cameras were turned off.