In the wake of a shooting that left dozens dead and injured more than 500 people in Las Vegas on Sunday, three of Nevada's congressional delegates are backing a bill that would ban devices that allow gunfire that mimics the rate of an automatic weapon.

Rhode Island Rep. David N. Cicilline introduced the bill — the Automatic Gunfire Prevention Act — on Wednesday, with Nevada Reps. Dina Titus, Jacky Rosen and Ruben Kihuen serving as co-sponsors. It would bar bump stocks, a legal device developed in the past decade that modifies a rifle and allows it to fire at a rate of 400 to 800 rounds per minute.

“The victims and families in Las Vegas don’t need an explanation about the difference between machine guns and firearms with bump stocks. They need action,” Titus, a member of the House Gun Violence Prevention Task Force, said in a statement. “I am introducing this legislation in hopes of closing this dangerous loophole and ensuring that civilians cannot modify their guns to fire nine bullets per second. This is the least that we can do.”

Authorities said Tuesday that they recovered a dozen bump stocks from the hotel room where the gunman, Stephen Paddock, carried out his attack in Las Vegas. Investigators found a total of 47 weapons, including rifles, shotguns and pistols, in the hotel and Paddock’s two homes.

The lawmakers' bill came the same day that President Donald Trump, speaking to reporters after visiting victims at University Medical Center in Las Vegas, brushed off a question about whether the country has a gun violence problem.

“We're not going to talk about that today. We won't talk about that,” he said, according to pool reports.

Titus, who appeared with Trump at a speech at Las Vegas Metropolitan Police’s headquarters earlier on Thursday, said in a statement that she had hand-delivered a letter to the president's staff asking the president to meet with the House Gun Violence Prevention Task Force, a group of Democratic lawmakers focused on reducing gun violence.

“You have the power to make real change in America and protect our communities from the senseless gun violence like we saw in Las Vegas,” the letter said.

Several Republican Senators have expressed support for banning or at least holding a hearing on bump stocks, including Wisconsin Sen. Ron Johnson and Texas Sen. John Cornyn. 

In a Wednesday interview with Fox News, Republican Congressman Mark Amodei said he wanted to study the bill's language before committing to vote for or against proposals banning the device.

Republican Sen. Dean Heller said in a statement to the Reno Gazette-Journal that he would be open to barring use of the device, but would prefer for the president to take action through regulations, as opposed to congressional action. The Bureau of Alcohol, Tobacco and Firearms declined to regulate the devices in 2010 largely because it was classified as a weapon part, which the agency doesn't have jurisdiction over.

"As I expressed earlier in the week, the use of the so-called 'bump stop' needs to be explored," he said. "Yesterday, I spoke to the President about reevaluating and reviewing the Obama Administration ruling that allows the use of the device on a semi-automatic weapon."

"It’s like everything else, show me the bill and I’ll tell you," he said. "I’ve looked at David Cicilline’s bill, which is great in terms of saying, ‘Hey, you know we think this ought to be illegal and that out to be illegal,’ the problem is that then there’s five lines right after that in the bill that go through a very broad description which could mean anything from grips to magazines to whatever."

Progressive groups, led by Battle Born Progress, held a press conference about 30 minutes after Trump left Las Vegas to call on members of Congress and local leaders to take steps to reduce gun violence, but focused more on a local issue — the implementation of a ballot measure requiring background checks on private gun sales or transfers.

Matthew De Falco, a member of a veterans group supportive of gun control, blamed Attorney General Adam Laxalt for failing to implement the measure, which the attorney general’s office has called “unenforceable” over a conflict with the FBI and how the ballot question was written.

“Anybody can walk into a gun show here in Las Vegas and purchase an arsenal of assault weapons,” he said. “Think about that.”

Talking points circulated to Trump surrogates in the wake of the shooting suggested they say things like “new laws won't stop a madman committed to harming innocent people. They will curtail the freedoms of law abiding citizens” and “let's gather the facts before we make sweeping policy arguments for curtailing the Second Amendment.”

But the shooting has reignited the discussion about gun laws among Democratic lawmakers, with Rep. Jacky Rosen arguing that “now is the time.”

“Congress must now find the strength to act. We must stand together to take meaningful action on gun violence that can help prevent another deadly mass shooting like this one,” she said. “We must act, so that families don't have to experience the grief and suffering that Las Vegas and its people are going through right now.”

This story was updated to reflect new information from congressional delegates, and updated on Thursday, Oct. 5 to include a response from Congressman Mark Amodei.