Civil liberties organisations and academics have raised alarm at the detention of Mahmoud Khalil, a Palestinian student activist at Columbia University, calling it a serious breach of free-speech rights under the administration of President Donald Trump, Al Jazeera reports.

Free speech groups point out that the Department of Homeland Security accused Khalil of leading “activities aligned with Hamas, a designated terrorist organization”.

But analysts note that the department’s allegation falls short of more tangible claims. US law, for instance, prohibits anyone in the country’s jurisdiction from providing “material support” to terrorist organisations.

“It’s a loophole so big that you could drive a truck through it,” Will Creeley, legal director of a free speech group, told Al Jazeera.

“I think what’s perhaps most dangerous about this moment is that, given the rhetoric coming out of the administration today, folks across the country are going to think twice before they criticise the government, whether it’s the US government or Israeli government, and that chill is a real problem,” he added.

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