Washington, US: Resistance to President Donald Trump’s crackdown on Muslim immigration mounted quickly on Saturday, with protests spreading across the country and the first legal challenge filed to an order branded as blatantly discriminatory.

Around 2,000 angry protesters flocked to New York’s John F. Kennedy International Airport after a dozen travelers were detained there, including two Iraqi men late Friday, shortly after Trump signed the travel ban.

Large protests also took place at the main airports for Washington, Chicago, Minneapolis, Denver, Los Angeles, San Francisco and Dallas, where USA Today said about 50 people were detained.

‘We knew that was coming—we were prepared,’ said Camille Mackler, a lawyer who heads legal initiatives at the New York Immigration Coalition, one of the groups that quickly mounted the demonstration there.

‘But we didn’t know when, and we couldn’t believe it would be immediate, that there’d be people in an airplane the moment the order was taking effect.’

The List Project, which helps Iraqis whose personal safety is threatened because they have worked for the United States, expressed outraged over the move, warning it put American lives at risk too.

‘I can’t say this in blunt-enough terms: you can’t screw over the people that risked their lives and bled for this country without consequences,’ wrote the project’s founder and director Kirk Johnson.

‘But here is President Trump, in his first week, suspending the refugee program through an executive order that creates no exceptions for the tens of thousands of Iraqis and Afghans who worked alongside our Marines, soldiers, diplomats and aid workers.’

He noted that of the approximately 800,000 refugees who have come to the United States since the September 11, 2001 attacks, none have been charged with domestic terror attacks.

The first lawsuit against Trump’s order was filed in a federal court by the American Civil Liberties Union and other advocacy groups after the two Iraqi men were detained.

The filing seeks class-action status in order to represent all refugees and travelers held up because of the presidential action.

An emergency hearing took place late Saturday in Brooklyn.

The legal challenge sought the release of the two Iraqi men 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 Representative Jerrold Nadler, who went there to press for their release.

‘We must fight’

Nadler posted on Twitter from the airport that he was trying to obtain the release of another Iraqi, who came to rejoin his wife and child already living in the United States as legal refugees, and the other 10 people.

‘We shouldn’t have to demand the release of refugees one by one,’ Nadler said. ‘We must fight this executive order in the streets, in the courts, anywhere, anytime. We must resist. We must fight.’

In the early afternoon, Darweesh left the airport to the welcoming shouts of demonstrators. ‘Welcome home! Muslims are welcome here!’ they yelled. ‘No hate, no fear!’

Trump says his crackdown is necessary to prevent ‘radical Islamic terrorists’ from entering the US.

The new Republican president’s sweeping order, signed Friday, bars the issuance of visas for 90 days to migrants or visitors from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen.

The order also suspended the US refugee resettlement program for at least 120 days while tough vetting rules are established. Syrian refugees were barred indefinitely, or until Trump decides they no longer pose a threat.

‘It’s really disappointing to see our country fighting against its own ideals of being a country that is supposed to be welcoming to everyone,’ said Ilhan Omar, a former refugee who is also the first Somali-American lawmaker in the United States.

‘It is important for us to remember that extremism and terrorism doesn’t have a nation. It doesn’t have a religion,’ she told CNN, noting that some of the 9/11 perpetrators’ home countries were not included in the ban.

‘We are exploiting the ignorance of some parts of our communities and fears they have of a faith they don’t understand and neighbors they haven’t taken a chance to learn the struggles and processes they have gone through to get here.’

A long battle

The rapid mobilization against the order suggests a protracted battle is shaping up between migrant advocates and Trump and his administration.

‘This is the opening salvo of a long battle that will go on in the courts,’ said Michael Kagan, a law professor at the University of Nevada Las Vegas who specializes in immigration issues.

He said the outcome of the legal battle is unclear because ‘we are in unchartered territory in modern America.’

The battle could end up in the US Supreme Court, which has not ruled on this type of immigration issue since the 1882 Chinese Exclusion Act.

During a period of severe discrimination against the Chinese, the law barred their entry into US territory for decades, including for Chinese natives who legally resided in the US and had temporarily left the country.

Similar cases could now multiply, according to Kagan.

A White House official said that holders of a green card, which allows permanent residence in the US and often takes years to obtain, who are abroad should first go to the US consulate to obtain a document allowing return to the US.

And green card holders in the US who want to travel abroad must obtain approval from a consulate official.

The State Department has said that people from the seven countries under the 90-day travel ban will be prohibited entry no matter their visa status. Only those holding a dual citizenship with the US will be allowed to enter.