Protesters reportedly plan to rally in New York City's Federal Plaza on Monday in support of Palestinian activist and Columbia University graduate student Mahmoud Khalil.
Khalil, who was involved in organizing the school's anti-Israel demonstrations, was arrested by Immigration and Customs Enforcement (ICE) agents Saturday night after being told his student visa was being rescinded, Amy Greer, Khalil's attorney, told The Associated Press.
Greer added that federal immigration authorities were notified that Khalil is a green card holder with permanent resident status but they "detained him anyway."
The People's Forum, which is coordinating Monday's planned rally, demanded on social media that Khalil be released without delay.
"Join us in the streets to demand the release of Mahmoud Khalil, a Palestinian student activist and recent Columbia graduate, who was abducted from his home by DHS agents last night and is now in ICE detention," the group wrote in a post on X. "Hands off our students! ICE off our campuses!"
According to the post, the rally, or "emergency mobilization," as the group called it, is slated to take place at 4 p.m. ET at the Jacob K. Javits Federal Building.
Greer said that her office does not know where Khalil is currently being detained and her office has filed a petition challenging the legality of his arrest.
Initially Khalil's wife, who is eight months pregnant and a U.S. citizen, was told he was at a facility in Elizabeth, New Jersey, but he was not there when she attempted to visit.
Khalil's lawyer told NBC News that reports indicate he may be in Louisiana, and the ICE website shows that Khalil may be at a Jena, Louisiana, immigrant detention facility.
"We will vigorously be pursuing Mahmoud's rights in court, and will continue our efforts to right this terrible and inexcusable — and calculated — wrong committed against him," Greer told NBC.
New York Immigration Coalition President and CEO Murad Awawdeh called Khalil's arrest a "blatantly unconstitutional act."
"America is supposed to be a country of laws, but this act by the DHS challenges that very concept," Awawdeh said in a statement. "DHS must immediately release Khalil, and our local elected officials must intervene in this unlawful and politically motivated detention of a New Yorker."
A Department of Homeland Security spokesperson told NBC that Khalil was arrested in coordination with ICE and the State Department because he "led activities aligned to Hamas, a designated terrorist organization." His apprehension was "in support of President Trump's executive orders prohibiting antisemitism," the spokesperson said.
The Trump administration "will be revoking the visas and/or green cards of Hamas supporters in America so they can be deported," Secretary of State Marco Rubio said in a Sunday post on X.