'I've serious concerns'

Republican Donald Trump was rushed off stage by security agents at a rally in Reno, Nevada, on Saturday night after a false alarm as someone in the crowd shouted "gun" during scuffles with a man who held up a 'Republicans against Trump' sign.

Two security agents seized Trump by the shoulders and hustled him backstage as police officers swarmed over a man in the front of the crowd and held him down and searched him before escorting him away with his hands behind his back.

Trump, seemingly unruffled, returned to the stage and continued his speech after a short time, saying "Nobody said it was going to be easy for us" and adding "We will never be stopped."

After being released, the man, Austyn Crites, who was apprehended told CBS News Reno affiliate KTVN-2 that he was a Republican supporter who attended the rally to express his opposition to Trump.

Crites said he wanted to contrast President Barack Obama's reaction to a protester during a rally a few days ago, in which he urged the crowd to respect the protester, with Trump's, saying he wanted "people to understand" the difference. "I have nothing against Trump supporters," Crites told the station. "We are all registered Republicans and support many of the same candidates for local offices. I have serious concern against Trump," he added.

In a statement, Trump thanked the Secret Service, Reno and Nevada law enforcement for "their fast and professional response."