Donald Trump supporters taunted and called for violence against a number of protesters at a tense rally in Las Vegas Monday night, reports from the scene say. BuzzFeed's McKay Coppins took a short video in which one man can be heard shouting "light the motherfucker on fire" as a black protester is being removed from the premises:

NBC's Benjy Sarlin says that one individual shouted the Nazi greeting "Sieg Heil" in the area of the same protester. Sarlin wrote that "Trump took the interruptions in stride and complained that they were the only way to get media outlets to turn their cameras towards his crowds to show off their size."

From Coppins' story:

"Physical altercations between protesters, security, and the occasional tough-guy supporter have been a running theme in Trump’s combative campaign this year—but Monday night was different. Reporters who regularly cover Trump said they had never seen anything like the fevered, frenzied mood that gripped the ballroom in Las Vegas."

A Republican presidential candidates' debate is scheduled for 8:30 p.m. ET Tuesday night at Vegas' Venetian Hotel & Casino. Trump leads national polls of likely Republican primary voters by a considerable margin.