[WATCH] Donald Trump rushed off stage by Secret Service agents after gun scare

Republican presidential nominee Donald Trump was rushed off stage by security agents on Saturday after a false alarm as someone in the crowd shouted “gun” during scuffles with a man who held up a ‘Republicans against Trump’ sign.

Trump shielded his eyes and looked into the crowd and was then suddenly removed from view by two agents as a disturbance unfolded near the stage.

Several witnesses said they heard shouts of “he’s got a gun”. The incident prompted the crowd to react in panic, with several hundred people surging towards the back of the hall in Reno.

The incident occurred as Trump and Democratic rival Hillary Clinton crisscrossed the United States a late push to win over undecided voters and make sure supporters turn out enthusiastically on Election Day.

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 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.

“I came here with this sign expecting boos ... But it was just a sign,” Austyn Crites said.

Crites said when he took it out, the crowd began to attack him, choking and beating him before "someone yelled about a gun."

After being held for a few hours' questioning and security and background checks, Crites said he was released, and that the police “did their job.”

Crites said he wanted to contrast President Barack Obama’s reaction to a protestor 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.

The Secret Service confirmed that the incident erupted when an unidentified individual in front of the stage shouted "gun."

“Immediately in front of the stage, an unidentified individual shouted ‘gun’. Secret Service agents and Reno police officers immediately apprehended the subject. Upon a thorough search of the subject and the surrounding area, no weapon was found,” a spokesman said in a statement.

Meanwhile, opinion polls show Democratic presidential Hillary Clinton hold a five-point lead over Trump in the latest Washington Post-ABC Tracking Poll released early on Sunday.

In the Post-ABC poll released on Friday, Clinton led Trump by 47% to 44%.

Clinton had an advantage in affirmative support, the poll said, with 55% of backers saying they are mainly supporting her, compared with 43% of Trump voters. More Trump voters say they “mainly oppose Clinton.”

Opinion polls show Clinton still holds advantages in states that could be critical in deciding the election. But her lead has narrowed after a revelation a week ago that the Federal Bureau of Investigation was looking into a new trove of emails as part of its probe into her handling of classified information while she was secretary of state.

A McClatchy-Marist opinion poll released on Saturday of voters nationwide showed Clinton leading by 1 percentage point compared to 6 percentage points in September.

A Reuters/Ipsos tracking poll on Saturday showed Clinton ahead by 4 percentage points nationally compared to 5 points on Friday, while an ABC News-Washington Post tracking poll had Clinton ahead by 48 to 43%.