On Friday (Oct. 30), a group of cars flying “Trump 2020” flags surrounded a Biden-Harris campaign bus on a highway in San Antonio, Texas. Video from the incident, which spread on social media, showed drivers circling around the bus and some even trying to force it off the road.

“These Trump supporters, many of whom were armed, surrounded the bus on the interstate and attempted to drive it off the road,” Eric Cervini, who said he traveled to Texas on behalf of the Biden-Harris campaign, tweeted. According to Cervini, one of the Trump supporters’ cars “ended up hitting a [Biden] staffer’s car.”

On Twitter, Travis County Democratic Party Chair Katie Naranjo also claimed that the drivers “followed the Biden bus throughout central Texas to intimidate Biden supporters.”

“They ran into a person’s car, yelling curse words and threats,” Naranjo added. “Don’t let bullies win, vote.”

The FBI is currently investigating the incident, according to a short statement the agency released Sunday evening (Nov. 1).

“FBI San Antonio is aware of the incident and investigating. No further information is available at this time,” the agency said.

The incident caused the Biden campaign to cancel at least one of their Texas events, NPR reports. Neither Joe Biden nor Kamala Harris was on the bus at the time.

Over the weekend, Trump applauded his supporters while speaking at a campaign event in Michigan.

“Did you see the way our people… they were, ya know, protecting this bus… because they’re nice,” he said. “They had hundreds of cars. Trump! Trump! Trump and the American flag.”

“In my opinion, these patriots did nothing wrong,” he added on Twitter. “Instead, the FBI & Justice should be investigating the terrorists, anarchists, and agitators of ANTIFA, who run around burning down our Democrat run cities and hurting our people!”

Biden responded to Trump’s comments and the incident while speaking to reporters on Sunday in Philadelphia.

“We’ve never had anything like this — at least we’ve never had a president who thinks it’s a good thing,” he said.

Florida Sen. Marco Rubio also drew criticism on Twitter after reportedly defending the drivers’ actions.

“I saw yesterday a video of these people in Texas. Did you see it? All the cars on the road; we love what they did,” the Republican said, according to The Washington Post.

See a clip from the incident below.