Green Party candidate Jill Stein was escorted off the Hofstra University campus Monday afternoon ahead of the evening's presidential debate there between Hillary Clinton and Donald Trump.

According to her Twitter account, Stein says officers from Hofstra and from Nassau County, New York, stopped her and asked her to produce credentials as she was on her way to a scheduled interview with MSNBC.

"We were on our way to an interview with @MSNBC when we were stopped by Hofstra security and Nassau County police just now," she tweeted . "Two police SUVs just pulled up and @MSNBC was questioned even though they had credentials for us at Hofstra for #debatenight."

Two police SUVs just pulled up and @MSNBC was questioned even though they had credentials for us at Hofstra for #debatenight. pic.twitter.com/1pbcIyS80g — Dr. Jill Stein (@DrJillStein) September 26, 2016

Police apparently allowed the interview to take place – Stein was on MSNBC' with reporter Hallie Jackson beginning at 1:52 p.m. – before escorting her from campus.

"Jill Stein was on the college campus," a spokeswoman for the Nassau County Police Department confirmed to U.S. News. "She was asked to verify the proper credentials. She did not have them, and she was escorted off the campus."

Hofstra's Department of Public Safety directed questions to Nassau police.

Stein gave what she described as an "impromptu press conference" while waiting for clearance to stay on campus and tweeted several photos of her being driven off the campus in a police van.

"We were immediately escorted off of the Hofstra campus after the press conference just now and told not to do any more press," she said .

After being escorted from Hofstra campus for doing an interview, police put us in a van which was stopped not once, but twice. #debatenight pic.twitter.com/IgQJMoCNWZ — Dr. Jill Stein (@DrJillStein) September 26, 2016

On Sunday, Stein told the university's student newspaper she planned to hold a rally and a "people's debate" on campus and attempt to force her way onto the debate stage.

"We will make an effort to get in … it's not likely," The Hofstra Chronicle quoted her as saying .

Nassau Deputy Police Chief McCarthy: "(Jill) is not public enemy number one." Interesting - why escort me from Hofstra for #debatenight? pic.twitter.com/63dDWLUk7r — Dr. Jill Stein (@DrJillStein) September 26, 2016

"What I'm really hoping to accomplish is what the American people are trying to accomplish, which is to open up the debates to have a fair and inclusive debate, at a time when the American people have rejected the two establishment candidates at record levels," Stein told MSNBC.

"Our campaign has really been blacked out. We've been virtually silenced by the media," she said. "We've essentially not been covered at all, which is why we're low in the polls. But as we begin to be seen and heard, we expect that to change."