Federal immigration authorities detained a Columbia University student early Thursday in an incident that sparked protests on campus and renewed scrutiny of immigration enforcement tactics at U.S. universities. Hours later, the government reversed course, releasing the student after New York City Mayor Zohran Mamdani raised the case directly with President Donald Trump.The student, Elmina "Ellie" Aghayeva, was taken into custody from a university‑owned residential building, according to Columbia officials. The university said agents entered the building under false pretenses, an allegation disputed by the Department of Homeland Security.By midafternoon, Mamdani said Trump had agreed to release Aghayeva after a conversation following an unrelated White House meeting focused primarily on housing policy.“I am safe and okay,” Aghayeva wrote shortly after her release in an Instagram story, adding that she was in “complete shock” and needed time to process what had happened....Mayor Raises Arrest During Meeting With TrumpMamdani said he brought up Aghayeva’s detention during a previously scheduled meeting with Trump, and later followed up with the president by phone. In a social media post, the mayor said Trump agreed to allow her release.The rapid turn of events marked the latest moment in the unusual relationship between Trump and Mamdani, a Democratic Socialist mayor whom Trump harshly criticized during the campaign but has since engaged on issues such as housing development.During the same discussions, Mamdani said he also urged Trump to drop immigration cases involving other current and former students facing deportation related to campus protests over the war in Gaza. The White House did not comment publicly on those requests.What We Know About Elmina AghayevaOriginally from Azerbaijan, Aghayeva is a senior at Columbia University with a valid visa, according to a statement released by her friends through the American Association of University Professors. She is majoring in neuroscience and political science.She has not been publicly linked by authorities or the university to the pro‑Palestinian demonstrations that roiled Columbia’s campus last year. Friends and faculty members say she is best known on campus and online as a content creator, sharing videos about student life and navigating college as an immigrant.Aghayeva has built a sizable social media following by posting day‑in‑the‑life content, study routines and advice for international students. She has more than 113,000 followers on TikTok and 107,000 followers on Instagram. Columbia officials declined to comment on the length of her enrollment or details of her immigration status, citing privacy concerns.After her release, she posted in an Instagram story, "Hi guys. I am so grateful for everyone of you. I just got out a little while ago. I am safe and okay. In an uber otw back home. I am so sorry, but I am in complete shock over what happened and my phone is blowing up with calls from reporters. I need a bit of time to process everything. I will come back soon but please don't worry."...Disputed Accounts of How Agents Entered Campus HousingColumbia officials said federal agents gained entry to Aghayeva’s apartment early Thursday by claiming they were searching for a missing person, an assertion echoed in a court filing by her attorneys.Soon after her detention, Aghayeva posted an Instagram story appearing to show her in the back of a vehicle, writing, “DHS illegally arrested me. Please help.”The Department of Homeland Security disputed parts of the university’s account. A DHS spokesperson said Aghayeva’s student visa had been terminated in 2016 for failing to attend classes and said she had no pending appeals or applications with the department.DHS also denied claims by some state officials that agents posed as New York City police officers. A Department of Homeland Security official told Newsweek: “ICE arrested Elmina (Ellie) Aghayeva, an illegal alien from Azerbaijan, whose student visa was terminated in 2016 under the Obama administration for failing to attend classes. The building manager and her roommate let officers into the apartment. She has no pending appeals or applications with DHS.”Immigration Tactics Draw Fresh ScrutinyThe incident has added to the growing debate over the use of deception by immigration agents, following recent cases in which federal officers have posed as utility workers or other service employees to make arrests.Such tactics are generally legal, but immigration attorneys and civil liberties advocates say they are being used more frequently as the Trump administration expands enforcement nationwide.In recent weeks, Trump has intensified criticism of several universities, including Harvard and UCLA, accusing them of failing to maintain order or control protests. The arrest of Aghayeva appeared to be the first federal enforcement action at Columbia since the university reached a financial settlement with the administration last summer.Campus Reaction and University ResponseThe detention prompted protests by students and faculty members, many of whom called on Columbia to strengthen protections for international students. The arrest followed last year’s detention of Mahmoud Khalil, a former graduate student and pro‑Palestinian activist whose deportation case remains ongoing.In an email to the university community on Thursday, Acting President Claire Shipman said residential staff had been reminded not to allow federal law enforcement into non‑public university spaces without a judicial warrant or subpoena.“If you encounter or observe DHS or ICE agents conducting enforcement activities on or near campus, immediately contact Public Safety,” Shipman wrote. “Do not allow them to enter non‑public areas or accept service of a warrant or subpoena.”The university said it is continuing to review the circumstances surrounding the arrest and will provide updates as more information becomes available.Updates: 2/26/26, 6:42 p.m. ET: This article was updated with new information and remarks.This article includes reporting by the Associated Press.