US rights groups filed a legal challenge on Saturday to President Donald Trump's order halting the arrival of refugees and travelers from seven Muslim countries.
Resistance to President Donald Trump's crackdown on Muslim immigration mounted quickly Saturday, with the first legal challenge filed to an order branded as blatantly discriminatory.
The suit suggests Trump's order temporarily halting all refugee arrivals and that of travelers from seven Muslim countries deemed to be terror threats faces tough battles ahead in US courts.
The first challenge was filed by the American Civil Liberties Union and other advocacy groups after two Iraqi men were detained Friday night at John F Kennedy Airport in New York.
It seeks their release on grounds of unlawful detention. One of them - Hameed Khalid Darweesh, who has worked as interpreter and in other roles for the US in Iraq - was in fact released on Saturday.
But 11 others remain detained at JFK, according to Democratic congressman Jerrold Nadler, who went there to press for the release of the first two.
"It is certainly mean-spirited and ill conceived," Nadler told CNN in reference to the crackdown. "It's certainly an instance of religious discrimination."
A demonstration was organized on short notice at JFK airport to protest the detentions, and another Democratic lawmaker, Nydia Velazquez, joined Nadler at the airport.
The advocacy groups asked that their challenge be given class action status so they can represent all refugees and travelers held up because of Trump's executive order on Friday.
The New York Times reported that airport authorities started detaining travelers as early as Friday night.
And reports abroad said people from the seven countries cited in the order were being prevented from boarding US-bound planes.
But it was not immediately clear how many travelers got caught up in Trump's crackdown, which he says is necessary to prevent Islamist terrorists from entering the US.
The largest African-American advocacy group in the US, the NAACP, said Trump's order will harm black Muslim families in America because many trace their heritage to Somalia, one of the seven countries cited in Trump's order.
"This will traumatise, terrorise, and potentially separate many American families," the NAACP Legal Defense Fund said.