Immigration and Customs Enforcement agents arrested Palestinian activist Mahmoud Khalil — a leader in Columbia University’s encampment movement — on Saturday night, claiming that his student visa had been revoked, according to attorney Amy Greer in a statement to ABC News.

However, Khalil is in the United States on a green card and not on a student visa, Greer said Sunday.

Despite informing agents about his legal status, ICE detained him, she said.

At one point during a phone call with agents, they hung up on Greer, a representative of her law firm told ABC News.

Greer is challenging his arrest and has been unable to locate where he is being held, she said.

“Overnight we filed a habeas corpus petition on Mahmoud’s behalf challenging the validity of his arrest and detention,” she said. “Currently we do not know Mahmoud’s precise whereabouts.”

Khalil’s wife, who is eight months pregnant and a U.S. citizen, was unable to find him at an ICE facility in Elizabeth, New Jersey, where he was purportedly transferred, Greer said — adding that he might have been transferred to Louisiana.

“ICE’s arrest and detention of Mahmoud follows the U.S. government’s open repression of student activism and political speech, specifically targeting students at Columbia University for criticism of Israel’s assault on Gaza,” she said. “The U.S. government has made clear that they will use immigration enforcement as a tool to suppress that speech.”

The alleged arrest occurred just days after President Donald Trump took to social media threatening to defund universities that allowed “illegal protests” and claiming “agitators” will be sent back to their home countries.

“All Federal Funding will STOP for any College, School, or University that allows illegal protests. Agitators will be imprisoned/or permanently sent back to the country from which they came. American students will be permanently expelled or, depending on on the crime, arrested. NO MASKS! Thank you for your attention to this matter,” Trump posted on Truth Social on March 4.

Columbia released the following statement on Sunday: “There have been reports of ICE around campus. Columbia has and will continue to follow the law. Consistent with our longstanding practice and the practice of cities and institutions throughout the country, law enforcement must have a judicial warrant to enter non-public University areas, including University buildings.”

“Columbia is committed to complying with all legal obligations and supporting our student body and campus community,” the statement continued.