Tehran - Iranians and Iraqis planning to fly to the United States were prevented from boarding on Saturday after US President Donald Trump's order to restrict arrivals from seven Muslim countries.
On Friday Trump signed a sweeping executive order to suspend the arrival of refugees and impose tough new controls on travellers from Iran, Iraq, Libya, Somalia, Syria and Yemen.
His move sparked widespread criticism and concern across the world.
Travellers from the Middle East were stopped from boarding US-bound planes and some already in the air when Trump signed the executive order were detained on arrival, the New York Times reported.
In Tehran, two travel agencies told AFP they had been instructed by Etihad Airways, Emirates and Turkish Airlines not to sell US tickets or allow Iranians holding American visas to board US-bound flights.
An Iranian studying in California visiting her home country said Saturday that she could not return because her ticket had been cancelled under the new restrictions.
"I had a ticket for Turkish Airlines on February 4, but it has been cancelled," the girl who did not wish to be identified told AFP.
"I've informed the university officials by mail and they were surprised. They are going to send me a letter so I can try fly from Europe."
Iranian President Hassan Rouhani did not comment directly on the visa ban Saturday, but did criticise Trump, saying that now was "not the time to build walls between nations".
- Valid visas -
"They have forgotten that the Berlin Wall collapsed many years ago. Even if there are walls between nations, they must be removed," Rouhani said.
More than a million Iranians live in the United States.
On Saturday in Egypt, a country not included in the new restrictions, an Iraqi couple and their two children were told they could not board an EgyptAir flight from Cairo to New York.
Airport officials said the four Iraqis all had American visas.
The New York Times reported that two Iraqi refugees who landed at New York's John F. Kennedy airport hours after Trump signed the tough new measures were detained by authorities.
On Saturday, the American Civil Liberties Union and other advocacy groups filed a legal challenge to Trump's order after the two Iraqi men were detained.
Lawyers representing the pair also filed a court appeal for their release, saying they were being unlawfully detained.
Reacting to Trump's move, the United Nations urged him to continue his country's "long tradition" of welcoming refugees and to ensure their equal treatment, regardless of race, nationality or religion.
French President Francois Hollande said Europe must have a "firm response" to Trump, and "when he refuses the arrival of refugees, while Europe has done its duty, we have to respond".
Hollande was due to speak with Trump later Saturday.
In Lebanon, Syrian refugees struggling to get by in makeshift camps shivered as temperatures dipped close to freezing and bemoaned their fate.
- Refugees stunned -
"What on earth have the Syrian people done to deserve this?" asked Abu Mahmoud al-Ghol, at one informal camp in the Marj area.
"And to think it's a democratic country doing it," said the 44-year-old.
Nearly six years of conflict in Syria have driven more than half the population from their homes, with many fleeing abroad and dreaming of new lives in the West.
Trump's executive order specifically says no visas will be issued for 90 days to migrants or visitors from the seven Muslim-majority countries.
It also specifically bars Syrian refugees from the United States indefinitely, or until Trump himself decides that they no longer pose a threat.
His decree suspends the entire US refugee resettlement programme for at least 120 days while tough new vetting rules are established.
Qatar Airways, which flies to around 15 American cities, said it would abide by the new regulations, adding however that passengers who have "the proper documentation" will be able fly.
A travel alert on its website said citizens of the seven barred countries could travel to the US if they have permanent residency there, or the so-called Green Card.
Government officials and their immediate family and international organisation representatives are exempt from the travel restrictions, the Gulf carrier said.
Trump's move has also angered one of Iran's most popular actresses, Taraneh Alidoosti who stars in the Oscar-nominated "The Salesman".
In a tweet the actress said she would boycott next month's Academy Awards ceremony in Los Angeles, saying: "Trump's visa ban for Iranians is racist. Whether this will include a cultural event or not, I won't attend the #AcademyAwards 2017."