Under pressure from Democratic Party leaders to denounce ugly violence by his supporters, Sen. Bernie Sanders instead struck back with a defiant statement Tuesday that dismissed complaints from Nevada Democrats as "nonsense" and asserted that his backers were not being treated with "fairness and respect."

It followed chaos at the Nevada Democratic Party Saturday night, where Sanders' supporters threw chairs, shouted down speakers and harassed the state party chair with death threats. Gravely alarmed, Democrats pressed Sanders to forcefully denounce it. But the dispute stands as the most public rift yet between the Sanders camp and other Democrats, and may undermine the party's attempt to maintain a unified front as frustration mounts among Hillary Clinton supporters that Sanders is continuing his campaign with no clear path to victory.

"Our campaign of course believes in non-violent change and it goes without saying that I condemn any and all forms of violence, including the personal harassment of individuals," Sanders said. But far from apologizing for anything his supporters did, Sanders repeated, in detail, their complaints that they were railroaded in the delegate process Saturday night, something Democratic officials deny. "The Democratic leadership used its power to prevent a fair and transparent process from taking place," he said.

Sanders issued his statement moments after speaking with Senate Democratic Leader Harry Reid, who told reporters that Sanders had condemned the violence in Las Vegas. "This is a test of leadership as we all know, and I'm hopeful and very confident Sen. Sanders will do the right thing," Reid said.

The head of the Democratic Party, Rep. Debbie Wasserman Schultz, D-Fla., also condemned he events in Las Vegas. "There is no excuse for what happened in Nevada, and it is incumbent upon all of us in positions of leadership to speak out," she said.

Sen. Barbara Boxer, D-Calif., who was booed when she spoke at the convention, told reporters Tuesday that she'd feared for her safety and said Sanders should give a "major speech" calling on his supporters to reject violence and opt for unity.

Sanders' statement seems unlikely to satisfy the demands from Reid, Wasserman Schultz, Boxer and others. It comes as Donald Trump is wrapping up the nomination on the Republican side, yet Democrats remain divided and now some Democrats fear that Sanders' supporters are starting to mimic backers of Trump in their sexist and aggressive behavior.

Democrats also fear that the unrest in Nevada could be a taste of what is to come at the Democratic Party convention in Philadelphia this summer.

Stephanie Schriock, president of EMILY's List, an influential political committee devoted to electing women that has come out in support of Clinton, said in a statement: "These disgraceful attacks are straight out of the Donald Trump playbook, and Bernie Sanders is the only person who can put a stop to them. Sanders needs to both forcefully denounce and apologize for his supporters' unacceptable behavior - not walk away."

Leading Democrats still stopped short of calling on Sanders to abandon his quixotic campaign, at least in public, training their concerns on the violence at the Nevada convention. "I am concerned if our party becomes labeled with the notion that we have this kind of violence," said Sen. Dick Durbin of Illinois, the No. 2 Senate Democrat.

Chair throwing, shouted profanities and even later death threats to party leaders marked Saturday's party meeting. The Nevada Democratic Party send a letter to the Democratic National Committee accusing supporters of presidential candidate Bernie Sanders of having a "penchant for extra-parliamentary behavior -- indeed, actual violence -- in place of democratic conduct in a convention setting."

Sanders dismissed that as "nonsense." "Our campaign has held giant rallies all across this country, including in high crime areas, and there have been zero reports of violence," he said.

"It is imperative that the Democratic leadership, both nationally and in the states, understand that the political world is changing and that millions of Americans are outraged  at establishment politics and establishment economics," he said.

Democratic officials released text messages and voicemails with threats against the Nevada Democratic Party chairwoman Roberta Lange. They included such comments as "Hey b-tch, loved how you broke the system, we know where you live, where you work, where you eat, where your kids go to school ... You made a bad choice, prepare for hell, calls won't stop."