Hundreds of vehicles flying Trump, MAGA and American flags caused delays around the New York metropolitan area on Sunday after they were seen stopping traffic to cheer and chant.

At around 10 a.m. ET Sunday, Maddy Pryor was driving north on the Garden State Parkway when she spotted numerous vehicles with MAGA flags driving near one another. At first, she thought it was just a coincidence, "but when we passed the Toms River service area, it became clear that it was something much more organized," she told CNN over Twitter.

"People were getting out of their cars both in the service area and on both sides of the parkway," Pryor said. "They would just get out and hold up their Trump flags (some were in Trump costumes) and shout and film things on their phone. They were causing traffic for miles and miles."

Tom Feeney, a spokesman for the New Jersey Turnpike Authority, which includes the Garden State Parkway, said that "several hundred vehicles" were involved in the demonstration on the parkway.

"As I understand, they met at the Monmouth service area (which is around milepost 100)," he told CNN over email. "They traveled North. I saw a video of them stopping on the roadway and blocking the northbound express lanes. Traffic backed up behind them for about five miles."

The vehicles left the highway at exit 135 near Clark Township at about 2 p.m. ET, Feeney said.

When contacted, the New Jersey State Police only said that police were aware of the demonstration on the parkway.

In New York at about 2:30 p.m. ET, roughly 300 vehicles were seen participating in a similar demonstration on the Mario Cuomo Bridge which spans the Hudson River, freelance journalist Yuki Iwamura told CNN.

"Some people got out of their cars and started chanting, but NY state troopers were also on the bridge also telling the cars to move along," Iwamura told CNN. "It was a very interesting to see a lot of Trump supporters in New York. Even if they weren't in Manhattan, it was rare for me to see that many Trump supporters in New York."

A New York state senator said the New York State Police should identify the participants and charge them for their "aggressive, dangerous, and reckless behavior."

"We all have the right to show support for a presidential candidate, but we do not have the right to endanger others and break the law," said Sen. David Carlucci, which represents the area that includes the Mario Cuomo Bridge.

CNN has reached out to the New York State Police and the governors of New York and New Jersey for comment.

The two incidents in New York and New Jersey follow one on a Texas highway Friday that is now under federal investigation.

The FBI is investigating the alleged harassment of a Joe Biden campaign by motorists displaying Trump 2020 flags, an FBI spokeswoman confirmed Sunday.

"FBI San Antonio is aware of the incident and investigating," FBI spokeswoman Michelle Lee told CNN.

The incident in Texas took place as the campaign bus was traveling from San Antonio to Austin as part of a push to urge Biden supporters to cast their ballots on the state's last day of early voting. A Biden campaign official described the motorists' actions as an attempt to slow down the bus and run it off the road.

On Sunday evening, U.S. President Donald Trump tweeted "these patriots did nothing wrong" in reaction to a statement from the FBI saying it was investigating an incident in Texas. The President claimed at a campaign rally on Sunday that his supporters were "protecting" the bus.

Biden told reporters in Texas Sunday evening, "We've never had anything like this."

"At least we've never had a president who thinks it's a good thing," he said.