Supporters of Bernie Sanders lost their cool at the Nevada Democratic convention Saturday night after the Hillary Clinton campaign successfully challenged the credentials of 60 Sanders delegates–mostly for not being official Democrats.

Videos quickly emerged online showing Sanders supporters clashing with Clinton supporters and shouting down Clinton surrogate Senator Barbara Boxer of California. According to Nevada political reporter Jon Ralston, security ended the convention when Bernie’s supporters ramped up the action.

Sources tell me that the lovely Bernie folks posted state Dem Chair @rlange9‘s cell #, and she has been getting a flood of nasty calls. 1/2 — Jon Ralston (@RalstonReports) May 15, 2016

Convention ended w/security shutting it down, Bernie folks rushed stage, yelling obscenities, throwing chairs. Unity Now! On to Philly 2/2 — Jon Ralston (@RalstonReports) May 15, 2016

Some exit polls from other states like West Virginia show significant percentages of Sanders’ supporters are unwilling to vote for the scandal-plagued Clinton campaign in a general election. That fact has made some Democrat insiders nervous, so much so that outgoing Senate Minority Leader Harry Reid issued a statement before the disastrous convention in Nevada yesterday urging calm between the two camps.

Convention ended w/security shutting it down, Bernie folks rushed stage, yelling obscenities, throwing chairs. Unity Now! On to Philly 2/2 — Jon Ralston (@RalstonReports) May 15, 2016

Sanders delegates felt “cheated” after the Clinton campaign challenged the standing of 60 Sanders delegates for not being registered Democrats. Sanders himself has been a registered independent during his time in the U.S. Senate. Clinton originally won the Nevada caucuses over Sanders by about 52 percent to 47 percent.