Democratic presidential hopeful Joe Biden hit out at White House rival Bernie Sanders’ past vote to exempt gun manufacturers from liability for shootings, in a Las Vegas speech close to the scene of the deadliest mass shooting in modern US history.

The former vice president devoted the majority of his speech at a Democratic gala on the Las Vegas Strip to deliver a fiery charge against the National Rifle Association and gun manufacturers, vowing to hold gun makers accountable if elected president.

“When I’m the president, we’ll take them on, remove the immunity and allow those parents who are trying now to sue for the pain and mayhem they have caused,” Mr Biden said on stage at the Tropicana casino-resort.

The resort sits adjacent to the area where a gunman in 2017 unleashed a torrent of gunfire on a country music festival.

Mr Biden, after decrying “carnage in our streets” and the anguish of families whose loved ones were killed in gun violence, said he “will not rest until they’re able to sue the gun manufacturers and get a ban on assault weapons”.

Joe Biden speaks at a campaign event in Las Vegas
Joe Biden speaks at a campaign event in Las Vegas (Patrick Semansky/AP)

Mr Biden did not cite Mr Sanders by name when referring to a 2005 federal law that shields gun makers from liability in most crimes, but said “some of the people running for office voted for that exemption”.

“Ladies and gentlemen, that immunity was granted. Granted. And it was a horrible, horrible decision,” he said.

Mr Sanders has since changed his position, co-sponsoring legislation to repeal the protections for gun manufacturers. He has also called in his campaign this year for sweeping gun control measures.

Mr Biden’s speech came after a frenzied Saturday of campaigning across Las Vegas on the first day of early voting in Nevada’s Democratic caucuses.

Mr Biden, counting on Nevada’s diverse population to keep his campaign alive after disappointing finishes in Iowa and New Hampshire, faces his biggest challenge in the Western state from Mr Sanders.

Mr Sanders, who was the first candidate to take to the stage on Saturday night, laced into billionaire candidate Mike Bloomberg, rattling off a list of heresies against the Democratic Party he accused the former New York mayor of committing.

Mr Bloomberg implemented “racist policies like stop and frisk” in New York, and opposed the minimum wage and higher taxes on the wealthy during the Obama administration, Mr Sanders said.

“The simple truth is that Mayor Bloomberg, with all his money, will not create the kind of excitement and energy we need to have the voter turnout we must have to defeat Donald Trump,” Mr Sanders said.

It was a rare attack by name from Mr Sanders. Mr Bloomberg is skipping the Nevada caucuses and was not at the Clark County Democratic Party dinner where Mr Sanders, Mr Biden and other 2020 contenders spoke.