Trump rushed off stage at rally

The 70-year-old Republican tycoon reappeared several minutes later to cheers from his fans, declaring: "Nobody said it was going to be easy for us, I want to thank the Secret Service."

"I want to thank the Secret Service. These guys are fantastic. They don't get enough credit. They don't get enough credit. They are amazing people."

Just before the fracas, Trump could be seen shielding his eyes from the lights in order to peer into the crowd as a struggle broke out.

There were signs of a fracas in the audience as three agents led Trump away, shielding his body, but once a suspect was in custody Trump returned to resume his stump speech.

Television footage showed a white male suspect pinioned on the ground by officers and searched, before he was led away by local law enforcement, including an armed response team in tactical dress with rifles.

The candidate appeared unrattled by the scuffle and spoke with his usual self-confidence, finishing his planned remarks and accepting the applause of the crowd before returning to his campaign plane safely.

"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 in a campaign statement.