Protesters gathered in front of the US Immigration and Customs Enforcement (ICE) building, urging authorities to free Mahmoud Khalil.
Waving Palestinian flags, the demonstrators chanted slogans such as "Mahmoud Khalil must be free, all the students must be free," and "Gaza, you are not alone."
Participants held signs with messages including: "Release Mahmoud Khalil," "Trump Hands Off Our Students," "Stop The Repression," and "End All US Aid To Israel."
Khalil, a Columbia University graduate who holds a US green card, was detained by ICE agents on March 8.
His arrest followed an order from US Secretary of State Marco Rubio to revoke his student visa and permanent residency.
The Trump administration accused Khalil of participating in “activities aligned with Hamas,” without providing any evidence.
Khalil had played a prominent role in pro-Palestinian demonstrations at Columbia University in the previous year.
His detention comes amid a series of executive orders by President Donald Trump targeting foreign nationals alleged to harbor “hostile attitudes” toward the United States.
The crackdown has included measures framed as combating antisemitism, leading to the deportation of international students involved in pro-Palestinian protests on US campuses.