DAYTON, Ohio (BLOOMBERG) - Security guards rushed the stage to protect Donald Trump at a rally in Dayton, Ohio, on Saturday, less than a day after thousands of protesters forced him to postpone a rally in Chicago.
Trump appeared to be have been alerted by a member of the crowd that someone was behind him, and he immediately jerked his head around as four agents surrounded him to provide a protective shield.
It was unclear what caused the incident. Trump continued with his speech as the crowd chanted "USA". He gave them thumbs up.
"Thank you for the warning," Trump told a member of the audience in the front row.
"I was ready for 'em, but it's much easier if the cops do it, don't we agree? What a great job. What a great job. And to think I've had such an easy life. What do I need this for? What do I need this for? I've done great. I love this country. We're going to make this country great again. It's payback time. These guys are so fantastic."
The incident comes after Trump abandoned a rally in Chicago in the face of furious protests.
The billionaire on Saturday called the disruption a "planned attack" from leftist groups and supporters of Senator Bernie Sanders, who's running for the Democratic nomination.
"When they have organised, professionally staged wise-guys - we've got to fight back. We've got to fight back," Trump said from inside of an airport hangar in Dayton.
"These other people, these other people - by the way, some represented Bernie, our Communist friend," Trump said.
"With Bernie, he should really get up and say to his people, 'Stop. Stop.' Not me."
A spokeswoman for Sanders did not immediately respond to a request for comment.
Trump also said that the activist group MoveOn.org was responsible for organising the protests.
"These are bad people. Let me tell you, these are people that truly don't want to see America great again. I'm telling you that," Trump said.
"We have got to toughen up now. We don't like it," Trump said.
"By doing what I did - that story is all over the world right now that we made the right decision under great pressure."
Friday's cancelled rally followed weeks of escalating tensions between protesters and some attendees at Trump's rallies, scuffles that have gone viral on social media.
Last week in New Orleans, local police struggled to remove dozens of protesters, and Trump's personal security had to assist.
In St Louis on Friday, hours before the protests erupted in Chicago, more than a dozen local police struggled for more than 10 minutes to remove a group of protesters who chanted that Trump was a racist.
Trump mused that he would be open to holding more town hall rallies, venues that are smaller to accommodate more personal one-on-one interaction between the voter and candidate.
"I'd actually like to have a couple of town hall meetings," Trump said.
Trump took time on Saturday to slam John Kasich, the Ohio governor who is vying with him for the lead ahead of the state's primary election on March 15.
Trump said that Kasich "got lucky" with the oil boom in the state which gave Ohio's economy a boost.
"Kasich is a baby," Trump said. "He can't be president."
The crowd of several hundred roared and chuckled in approval.