Mr Khalil, a Columbia University graduate and permanent US resident, played a key role in last year’s Gaza war protests at the Ivy League campus in New York City.

The arrest is part of President Donald Trump’s pledge to crackdown on pro-Palestinian protesters on college campuses, in what he called “the first arrest of many to come”.

Protesters gathered in New York City on Monday afternoon pushing for Mr Khalil’s release and condemning the Trump administration’s actions.

A crowd waving Palestinian flags gathered in Lower Manhattan’s Foley Square soon after it was reported that the US had attempted to deport Khalil. The protesters later marched further south toward city hall. At least one person was detained.

“We’re facing a horrifying reality that our own student, a member of the Columbia community, has become a political prisoner here in the United States,” Columbia University Professor Michael Thaddeus said in a statement.

The judge set a hearing for Wednesday where Mr Khalil is expected to make an appearance, according to court documents.

Immigration and Customs Enforcement (ICE) agents informed Mr Khalil they were revoking his student visa and green card upon taking him into custody on Saturday, his lawyer said.

The Department of Homeland Security (DHS) accused the former student of “leading activities aligned to Hamas” but provided no details. The BBC has asked the agency for further information on the allegations.

Trump has previously stated that foreign students found to be “terrorist sympathisers” would face deportation. Mr Khalil is the first known detainee under this policy.

His lawyer, Amy Greer, condemned his detention as “terrible and inexcusable”, calling it part of “the US government’s open repression of student activism and political speech”.

Mr Khalil, a Palestinian refugee who was born in Syria, has not been charged with any crime.

ICE agents detained him at his university-owned Manhattan apartment and initially placed him in a New Jersey immigration facility before transferring him to a detention centre in Jena, Louisiana, according to ICE records.

His attorney claims ICE also threatened to arrest his wife, an American citizen who is eight months pregnant. When she attempted to visit him in New Jersey, officials told her he was not there.

Columbia University stated that law enforcement can enter campus property with a warrant but denied that university leadership had invited ICE agents.

On Sunday, Secretary of State Marco Rubio reaffirmed the administration’s stance, posting on X: “We will be revoking the visas and/or green cards of Hamas supporters in America so they can be deported.

The Trump administration announced last week it was rescinding $400m (£310m) in federal grants to Columbia, accusing it of failing to fight antisemitism on campus.

Columbia was the epicentre last year of pro-Palestinian student protests nationwide against the war in Gaza and US support for Israel.

Mr Khalil was lead negotiator for Columbia University Apartheid Divest when its protesters set up a huge tent encampment on the university lawn in protest against the Gaza war.

He later told the BBC he had been temporarily suspended by the university, where he was a graduate student at the School of International and Public Affairs.

New York Civil Liberties Union President Donna Lieberman called his deportation “targeted retaliation and an extreme attack on the First Amendment.”

New York Attorney General Letitia James said she was “extremely concerned” and monitoring the case.

Some Jewish students at Columbia said that the protest rhetoric had at times crossed the line into antisemitism last year. School officials raised this and other safety concerns when they announced that classes would be fully remote until the end of the 2024 spring semester.

But many contested the accusations of antisemitism, and Jewish students also joined the pro-Palestinian demonstrations.

Carly, a Jewish-American graduate student at Columbia and a friend of Mr Khalil, rejected the characterisation. She told the BBC that the detainee was a “very, very caring soul”.

“He has been very targeted online and just seeing how he has been so misrepresented, it’s very painful, as someone who knows him on a personal level,” said Carly, who declined to share her surname for privacy reasons.

Speaking on Fox News, Trump’s border tsar Tom Homan alleged that Mr Khalil had violated the terms of his visa by “locking down buildings and destroying property”.

The Israeli military launched its campaign against Hamas in response to an unprecedented cross-border attack into Israel on 7 October 2023, which left about 1,200 people dead and 251 taken hostage.

More than 48,000 Palestinians in Gaza have been killed in Israel’s military action, according to the Hamas-run health ministry.

The court said it handed down sentences of between two to 10 years’ imprisonment in connection with attacks on military facilities last year.

Protests erupted nationwide in May 2023 after security forces arrested Khan during his appearance at the High Court on charges of corruption – allegations that he called politically motivated.

Thousands of Khan’s supporters stormed government buildings and military installations and the government responded with a crackdown on his Pakistan Tehreek-e-Insaf (PTI) party.

At least 1,400 protesters were arrested last year, police said, but only about 100 of the people detained have faced military trials.

The army said full justice will only be served when the masterminds behind the protests are punished.

A Supreme Court ruling last year provisionally allowed military courts to try civilian suspects.

“All sentences announced by the military courts are disproportionate and excessive,” a spokesman for the PTI party said, adding that “these sentences are rejected”.

Amnesty International has said that trying civilians in military courts is “contrary to international law” and adds that it is “purely an intimidation tactic, designed to crack down on dissent”.

Pakistan’s army has heavily influenced the nuclear-armed country for most of its existence and is a crucial behind-the-scenes player.

Former Pakistan cricket star Khan was elected prime minister in 2018, but fell out with the country’s powerful army.

After a series of defections, he lost his majority in parliament.

He was ousted after he lost a confidence vote in April 2022, four years into his tenure.

Since then, he had been a vocal critic of the government and the country’s army.

In October 2022, he was disqualified from holding public office, accused of incorrectly declaring details of presents from foreign dignitaries and proceeds from their alleged sale.

The next month, he survived a gun attack on his convoy while holding a protest march.

The individuals will face travel bans and asset freezes for “violating human rights”, the Foreign Office said, adding that the sanctions were imposed in coordination with the US.

Foreign Secretary David Lammy said: “The shocking violence inflicted upon protestors, opposition leaders and journalists is an egregious attack on democracy.”

The country has seen months of violent clashes between protesters and police since parliamentary elections held in October, most recently over the government’s decision to pause EU accession talks.

The UK has already paused the annual Wardrop Dialogue strategic dialogue and restricted defence cooperation with Georgia.

The announcement comes days after former Manchester City footballer Mikheil Kavelashvili was appointed the country’s president.Kavelashvili is viewed as an ally of the anti-Western ruling party, in contrast to the strongly pro-European incumbent Salome Zourabichvili.

Zourabichvili has pledged not to leave office when her term ends on 29 December, saying her successor was chosen illegitimately.

Protests against Georgian Dream began immediately after parliamentary elections in October elections, but they intensified at the end of November when the government announced it was putting EU accession negotiations on hold until 2028.

Four out of every five voters are said to back joining the EU, a goal inscribed in the constitution.The main avenue outside parliament has been regularly filled with protesters draped in EU flags, demanding new elections.

Demonstrators using fireworks have been met with a harsh response from police, who have used batons, tear gas, rubber bullets, and water cannons to disperse protesters.

Both the EU and US have condemned the government for democratic backsliding. More than 460 people have been detained across Georgia over the past two weeks, according to Transparency International.

More than 300 have been ill-treated or tortured, the organisation says, including dozens of members of the media. Last weekend, thugs were filmed attacking a TV reporter and cameraman.

Protesters have called on the international community to impose sanctions on top government officials.

Pro-government groups have also waged a campaign of harassment towards civil society activists, beating them outside homes, and carrying out arbitrary arrests.