The GOP nominee was not injured in the incident and returned to the stage minutes later to finish his speech. A law enforcement official told CNN no weapon was discovered.
Trump was in the middle of his stump speech when the incident occurred. He then looked into the crowd, his hand over his eyes to block the glare from the stage lights, when Secret Service agents grabbed him and escorted him off the stage. Trump ducked his head as he left the stage.
The crowd surged backward, some supporters with frightened looks on their faces, as the Secret Service and police tactical units rushed in to detain a man.
The detained man was then rushed by a throng of police officers, Secret Service agents and SWAT officers armed with assault rifles to a side room.
Several attendees at the rally said they saw a Trump supporter raise up a sign and then a scuffle ensued.
Further details were not immediately available. A spokesman for the Secret Service did not immediately have information and a message left with the Trump campaign was not immediately returned. A spokesman for the Reno police department directed media inquiries to the Secret Service.
The Republican nominee returned to the stage several minutes later.
“Nobody said it was going to be easy for us, but we will never be stopped. We will never be stopped. I want to thank the Secret Service. These guys are fantastic.”
He then returned to his regular stump speech.
Trump is scheduled to speak later Saturday night at a rally in Denver.
He later issued a statement about the incident.
“I would like to thank the United States Secret Service and the law enforcement resources in Reno and the state of Nevada for their fast and professional response,” he said. “I also want to thank the many thousands of people present for their unwavering and unbelievable support. Nothing will stop us — we will make America great again!