The Nevada State Democratic Party warned the Democratic National Committee Monday that supporters of Vermont Sen. Bernie Sanders have displayed a "penchant for ... actual violence' and could disrupt this summer's Democratic National Convention in Philadelphia.

The allegation is the latest fallout from a divisive Nevada Democratic convention that had to be shut down Saturday night because security at the Paris Las Vegas hotel could no longer ensure order. The gathering closed with some Sanders supporters throwing chairs; later, some made death threats against state party chairwoman Roberta Lange.

Sanders' backers had been protesting convention rules that ultimately led to Hillary Clinton winning more pledged delegates. Clinton won the state's caucuses in February, 53-47, but Sanders backers hoped to pick up extra delegates by packing county and state party gatherings.

Sanders had released a statement Friday night asking supporters to work "together respectfully and constructively" at the convention. But the state party alleged in its letter to the co-chairs of the DNC Rules and By-laws committee, "The explosive situation arose in large part because a portion of the community of Sanders delegates arrived at the Nevada Democratic State Convention believing itself to be a vanguard intent upon sparking a street-fight rather than attending an orderly political party process."

Michael Briggs, a Sanders campaign spokesman, said, "We do not condone violence or encourage violence or even threats of violence." He added that the campaign "had no role in encouraging the activity that the party is complaining about. We have a First Amendment and respect the rights of the people to make their voices heard."

On Saturday, Sanders backers shouted down the keynote speaker, Sen. Barbara Boxer, D-Calif., and others they thought were tilting the rules in Clinton's favor. Protesters shouted obscenities and rushed the dais to protest rulings.

"We believe, unfortunately, that the tactics and behavior on display here in Nevada are harbingers of things to come as Democrats gather in Philadelphia in July for our National Convention," the state party's general counsel, Bradley S. Schrager wrote in a letter to the DNC. "We write to alert you to what we perceive as the Sanders campaign's penchant for extra-parliamentary behavior — indeed, actual violence — in place of democratic conduct in a convention setting, and furthermore what we can only describe as their encouragement of, and complicity in, a very dangerous atmosphere that ended in chaos and physical threats to fellow Democrats."

Several Sanders backers have condemned some of the threats against Lange and other actions Saturday. Former state assemblywoman Lucy Flores, a current congressional candidate, said in a statement: "There were actions over the weekend and at the Democratic convention that very clearly crossed the line. Progressives need to speak out against those: Making threats against someone's life, defacing private property, and hurling vulgar language at our female leaders."

State party offices remained closed Monday for security reasons after Sanders supporters posted Lange's home and business addresses, email and cell phone number online. Copies of angry and threatening texts to Lange were included with the letter.

Lange said she'd been receiving hundreds of profanity-laced calls and texts from inside and outside of the U.S., threatening her life and her family. Lange said the restaurant where she works has received so many calls it had to unplug the phone.

"It is endless, and the longer it goes the worse it gets," Lange said in an interview. "I feel threatened everywhere I go."

The Associated Press contributed to this report.