Speaking while campaigning in the Philadelphia suburbs, Biden referenced the effort by Trump supporters late last week to swarm a Democratic campaign bus and drive it off the road in Texas.

Trump tweeted a video of the caravan and declared, “I LOVE TEXAS!”

Biden also referenced reports that Trump supporters shut down a major roadway in New Jersey.

“We’ve never had anything like this. At least we’ve never had a president who thinks it’s a good thing,” Biden said on Sunday.

The FBI said it was investigating the incident, which took place on Friday on an interstate highway and forced Democrats to cancel two scheduled campaign events for “security reasons”.

Local media reported about 100 vehicles surrounded the Biden bus and collided with another Biden campaign vehicle as they were travelling from San Antonio to Austin.

Images posted on social media show a long line of vehicles with Trump flags following, surrounding and blocking the bus identified on its exterior as belonging to the Joe Biden-Kamala Harris campaign.

Biden’s campaign team called the police, who made no arrests.

The presidential contest has proven unexpectedly close in Texas, which is typically a reliable Republican state.

-AAP