Hillary Clinton. AP Photo/Patrick Semansky Former Secretary of State Hillary Clinton went after the National Rifle Association in response to Sunday night's mass shooting in Las Vegas, the deadliest in modern US history.

"Las Vegas, we are grieving with you — the victims, those who lost loved ones, the responders, & all affected by this cold-blooded massacre," Clinton, the 2016 Democratic presidential nominee, tweeted.

In a series of follow-up tweets, Clinton wrote that the country "must put politics aside" and "stand up to the NRA," specifically citing the organization's stance on gun silencers.

"The crowd fled at the sound of gunshots," Clinton tweeted. "Imagine the deaths if the shooter had a silencer, which the NRA wants to make easier to get.

"Our grief isn't enough," she continued. "We can and must put politics aside, stand up to the NRA, and work together to try to stop this from happening again."

The NRA is supporting a congressional bill to remove a $200 fee on gun silencers. The bill, called the Hearing Protection Act, is being promoted as a public health measure, according to The Washington Post.

At least 59 people were killed and 527 were injured in the shooting late Sunday night. Police have named 64-year-old Stephen Paddock as the gunman. He had at least 10 rifles in the hotel room where he carried out the shooting, police said.