Republicans said Tuesday they had halted plans, at least temporarily, to advance a bill that would make it easier for Americans to buy gun silencers.

The shooting in Las Vegas on Sunday night that left at least 58 dead and hundreds injured magnified the focus on the legislation, which passed a House committee last month.

“That bill is not scheduled now; I don’t know when it’s going to be scheduled,” House Speaker Paul D. Ryan (R-Wis.) told reporters. “Right now we’re focused on passing our budget.”

The Las Vegas shooting is the latest incident of mass violence to put Republican lawmakers on the defensive over their opposition to new gun restrictions — and, in some cases, their efforts to eliminate existing ones.

Here’s how frustrated Democrats have responded to Las Vegas

The Sportsmen’s Heritage and Recreational Enhancement Act passed the House Natural Resources Committee on a party-line vote on Sept. 13. Owning a firearm silencer requires a special license from the Bureau of Alcohol, Tobacco, Firearms and Explosives, similar to the regulations surrounding machine guns and explosives. The House bill would instead treat silencers like firearms, requiring only a federal background check.

The legislation also includes provisions that would loosen restrictions on transporting firearms across state lines and prevent certain types of ammunition from being designated as “armor-piercing” and thus subject to tighter federal oversight.

House Rules Committee Chairman Pete Sessions (R-Tex.) acknowledged that the Las Vegas shooting was a “complicating issue” with the bill — though he did not rule out that it could come to the floor later in the current Congress.

“Nobody wants to bring up something when there’s something like that,” he said. “We wouldn’t want to bring up any difficult issue.”

Opponents of the silencer provision say that it could make it harder to identify a shooter during an incident such as the one in Las Vegas. Its proponents argue that the devices only muffle — not silence — a high-powered rifle, helping to protect the hearing of law-abiding shooters.

Law enforcement officials have not indicated that the Las Vegas shooter, 64-year-old retired accountant Stephen Paddock, used a silencer in his attack. But they have said another controversial accessory was found at the scene: a “bump stock,” which can allow a legal semiautomatic rifles to fire as rapidly as more heavily restricted fully automatic weapons can.

Sen. Dianne Feinstein (D-Calif.) called attention Tuesday to the legal status of bump stocks, noting the devices are available online for less than $200 and “inflict absolute carnage.”

“I’m looking at how best to proceed with legislation to finally close this loophole,” she said. “This is the least we should do in the wake of the deadliest mass shooting in U.S. history.”

Even some outspoken conservatives suggested that bump stocks might need to be restricted. The chairman of the House Freedom Caucus, a hard-line group whose members are generally strong proponents of gun rights, said “greater scrutiny” is warranted.

“You have to have a special class of license to have an automatic weapon, and so if this is something to bypass this, I think it becomes something that we obviously need to look at in the future,” Rep. Mark Meadows (R-N.C.) said. He added that the aftermath of a tragedy “is not the best time to look at any legislation.”

Democrats again argued Tuesday that there is no better time to highlight congressional inaction on guns. They blamed Ryan, for instance, for refusing to allow votes on a universal background check bill and blocking requests for hearings on the issue.

House Minority Leader Nancy Pelosi (D-Calif.) asked Ryan on Monday to launch a bipartisan special committee on gun violence, but Democrats said Ryan turned down the request. They also said he rejected a proposal from Rep. John Lewis (D-Ga.) for a show of unity and action to curb acts of gun violence.

“We were told in caucus today that the response was, if it has to do with policy, it was a nonstarter,” said Rep. Mike Thompson (D-Calif.), chairman of the House Gun Violence Prevention Task Force.

After last year’s nightclub shooting in Orlando, Democrats occupied the House floor for more than 24 hours to draw attention to efforts to expand federal background checks for gun buyers.

Rep. Linda T. Sánchez (D-Calif.), vice chair of the House Democratic Caucus, said Tuesday that there are no plans for another sit-in or for a petition to force a vote on any of the gun bills Democrats have proposed so far.

Democrats are planning a rally on the steps of the Capitol on Wednesday morning to call attention to Republicans’ inaction on gun control. The event will be led by Lewis, Pelosi and former congresswoman Gabrielle Giffords, who was shot in the head by a gunman who opened fire at a constituent event in her Arizona district in 2011.

At a closed-door meeting of House Republicans on Tuesday, there was talk about what happened Sunday in Las Vegas, but, according to several members, little was said about a legislative response.

“We all discussed the tragedy and certainly all of our thoughts and prayers go out to them, and that was pretty much the total extent of it,” said Rep. Chris Collins (R-N.Y.).

Collins added that Congress ought to focus on mental health rather than gun restrictions: “We are not going to knee-jerk react to every situation. The Democrats continue to want to say, when a mentally deranged person does what they do, it’s the gun’s fault, not the shooter’s fault. . . . People focused on mayhem and the kind of evil this person was — in their heart, you can’t stop them. They will do it one way or the other. You can’t stop a mentally deranged person.”

Law enforcement officials have not given any indication that Paddock was ever treated for mental illness or showed any signs of instability.

Ryan also told reporters that the focus ought to be on mental health rather than gun restrictions. Congress passed an overhaul of mental health laws last year, but that legislation did not include some firearm restrictions that gun-control advocates had pushed for.

“One of the things we’ve learned from these shootings is that often, underneath this, there is a diagnosis of mental illness,” Ryan said. “ . . . Mental health reform is a critical ingredient to making sure that we can try to prevent some of these things from happening.”

Rep. Mark Amodei (R-Nev.), who represents the northern part of the state, said it is a “humbling time” for Nevadans but did not mention the need for any specific legislative response.

"There's time in the coming weeks to find those answers and do those sorts of things that we need to do and see what lessons are learned," he said. "But I think right now, it's just that humility — thoughts and prayers to those folks that were affected, both those that are here and those that are gone."