When Negah Hekmati and her family, who are American citizens, arrived at the US-Canada border early on Sunday, skis strapped to the rack on top of their car, she figured they would be waved through and quickly be on their way.

With Nexus cards in hand — a pre-screening service for expedited travel over the border — Ms Hekmati, 38, was expecting little more than the two more hours of driving that remained before she and her husband could put their five-year-old daughter and eight-year-old son to bed in their suburban Seattle home.

But the shock waves of Donald Trump’s decision to kill an Iranian general just days earlier appeared to have already reached their far northwestern corner of the contiguous United States: Even after several no-hassle trips between their home and Vancouver over the holidays, the family of American citizens found themselves ushered into a room where they waited for roughly five hours alongside as many as 200 others of Iranian descent, some of whom claimed they were held much longer than that.

As those hours wore on, Ms Hekmati said the 12-year-old daughter of friends travelling with them couldn’t sleep for fear she would wake up with her parents in jail. And Ms Hekmati’s own daughter, born in the US, suggested that they all avoid speaking Persian — a temporary abandonment of heritage by a citizen of a country that prides itself on cultural diversity.

“The problem is I don’t want my kids to be OK with such things,” Ms Hekmati told The Independent. “I’m a proud Iranian-American. My kids can speak Farsi fluently, both of them. And I want them to be proud of their ancestors, their heritage. I don’t want them to be scared.”

US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Show all 35 1 /35 US airstrike kills Iran's Qassem Soleimani: Fallout in pictures US airstrike kills Iran's Qassem Soleimani: Fallout in pictures This photo released by the Iraqi Prime Minister Press Office shows a burning vehicle at the Baghdad International Airport following an airstrike in Baghdad, Iraq, early Friday 3 January AP US airstrike kills Iran's Qassem Soleimani: Fallout in pictures The wreckage of the car in which general Soleimani was travelling when a targeted US airstrike struck outside Baghdad International Airport on 3 January Ahmad Al Mukhtar via Reuters US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Demonstrators burn the US and British flags during a protest in Tehran after general Soleimani was killed in a targeted airstrike by American forces Reuters US airstrike kills Iran's Qassem Soleimani: Fallout in pictures A burning vehicle at the Baghdad International Airport following an airstrike. The Pentagon said Thursday that the US military has killed general Qassem Soleimani, the head of Iran's elite Quds Force, at the direction of Donald Trump AP US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Protesters burn Israeli and US flags as thousands of Iranians take to the streets to mourn the death of general Soleimani at the hands of America EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Supporters of Donald Trump pray at an 'Evangelicals for Trump' campaign event held on the day following the killing of general Soleimani. At the event, the president praised the "flawless strike that eliminated the terrorist ringleader" AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures A huge procession of mourners gather in Baghdad for the funeral of general Soleimani on 4 January AP US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Thousands of Iranians take to the streets to mourn the death of Soleimani during an anti-US demonstration to condemn the killing of Soleimani, after Friday prayers in Tehran, Iran EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Iraqis perform a mourning prayer for slain major general Qasem Soleimani of the Iranian Revolutionary Guards at the Great Mosque of Kufa AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures A billboard reading 'Death to America and Israel', installed by Iran-backed shiite armed groups at a street in Jadriyah district in Baghdad, Iraq EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures A handout picture provided by the office of Iran's supreme leader Ayatollah Ali Khamenei shows him visiting the family of Soleiman KHAMENEI.IR/AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Thousands of Iranians take to the streets in Tehran EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Pakistani Shiite Muslims burn a mock of a US flag as they hold pictures of General Qasem Soleimani during a protest against the USA, outside the US Consulate in Lahore, Pakistan EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Iran's Ambassador to Lebanon Mohammed Jalal Feiruznia, looks to a portrait of Soleimani, as he receives condolences at the Iranian embassy, in Beirut, Lebanon AP US airstrike kills Iran's Qassem Soleimani: Fallout in pictures People make their way on the street while a screen on the wall of a cinema shows a portrait Soleimani in Tehran AP US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Aziz Asmar, one of two Syrian painters who completed a mural following the killing of Iranian Revolutionary Guards commander Qasem Soleimani poses next to his creation in the rebel-held Syrian town of Dana in the northwestern province of Idlib AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures A demonstration in Tehran AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures An anti-US demonstration to condemn the killing of Soleimani, after Friday prayers in Tehran EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Mujtaba al-Husseini, the representative of Iran's supreme leader Ayatollah Ali Khamenei, delivers a speech in the holy shrine city of Najaf AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Pakistani Shiite Muslims burn a mock of a US and Israeli flags as they hold pictures of General Qasem Soleimani during a protest against the USA, outside the US Consulate in Lahore, Pakistan EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Protesters demonstrate in Tehran AP US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Pakistani Shi'ite Muslims hold pictures of General Qasem Soleimani during a protest against the USA, in Peshawar, Pakistan EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Protesters, holding a photograph of the leader of the People's Mujahedin of Iran Massoud Rajavi, outside Downing Street in London PA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Protesters burn a US flag in Tehran AP US airstrike kills Iran's Qassem Soleimani: Fallout in pictures A Syrian man offers sweets to children to mark the killing AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Iranian worshippers attend a mourning prayer for Soleimani in Iran's capital Tehran AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Kashmiri Shiite Muslims shout anti American and anti Israel slogans during a protest AP US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Iranian worshipers chant slogans during Friday prayers Reuters US airstrike kills Iran's Qassem Soleimani: Fallout in pictures A protest against the USA, in Islamabad, Pakistan EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Iranians burn a US flag in Tehran EPA US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Supporters of the National Council of Resistance of Iran in Germany (NWRI) protest outside Iran's embassy in Berlin, Germany Reuters US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Supporters of the National Council of Resistance of Iran in Germany (NWRI) protest outside Iran's embassy in Berlin Reuters US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Iranian worshippers in Tehran AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Vehicles of the United Nations Interim Forces in Lebanon (UNIFIL) patrol a road in the southern Lebanese town of Kfar Kila near the border with Israel. Following morning's killing of Major General Qasem Soleimani, Lebanon's Iran-backed Hezbollah movement called for the missile strike by Israel's closest ally, to be avenged AFP via Getty US airstrike kills Iran's Qassem Soleimani: Fallout in pictures Iranian women take to the streets in Tehran EPA

Those stopped and questioned at the US-Canada border over the weekend included up to 200 Iranian-Americans, all of whom were ushered into a room at the Blaine Border Checkpoint and asked to wait, told only that new procedure had necessitated the extended delay.

The delays have caught the attention of several prominent politicians, pundits and civil rights groups, including congresswoman Pramila Jayapal and congressman Ro Khanna, both of whom say their offices are monitoring the situation. The governor of Washington, Jay Inslee, has also spoken out on the issue to condemn the US government’s actions.

For some, the reports of these detentions has evoked a sordid American history dating back to the Second World War, when the US opened internment camps for Japanese Americans fearing internal uprisings from descendants of a foreign power it was at war with.

“From a policy standpoint, detaining and questioning, without charge, innocent Americans because of their ethnicity and then releasing them is not that far removed from the even more insidious kind of permanent detention without charge we saw imposed on Japanese Americans in World War II,” said Patrick Eddington, a policy analyst in national security and civil liberties at the Cato Institute, noting that US Supreme Court has as recently as 2018 in its decision on the Trump v Hawaii case — which undercut Mr Trump's attempt to implement a travel ban on predominantly Muslim countries — determined that it is unconstitutional for the executive branch to forcibly relocate US citizens based on race.

Mr Eddington told The Independent: “Congress needs to investigate whether the Administration has, in violation of the Supreme Court ruling in Trump v Hawaii, actively developed plans for the identification and detention of Iranian Americans or any other American ethnic group in the event of another American war in the Arab and Muslim .”

The group of travellers in northwest Washington included concert-goers who had travelled to Vancouver for an Iranian pop concert, alongside several families like the Hekmatis who had visited friends or family in Canada. Many of those families included children born in the United States to parents who had become naturalized American citizens after moving to the western hemisphere decades ago. On the other side of the US, at New York's JFK airport, at least one other American citizen — a professor at the University of Pennsylvania who is of Iranian descent — was also questioned briefly, showing that the reportedly new policies may not be isolated to one point of entry.

The rising tensions between the US and Iran explained

In many cases, according to interviews with individuals who were stopped or whose family was stopped, the agents were civil, and provided snacks and drinks as they worked through what was described as a new policy. They were asked for personal details like parent names, the names and locations of their high schools or colleges, and in some instances for the handles of social media accounts. Some were asked for their thoughts on the unfolding situation in Iraq and Iran where mourners have demonstrators have protested against the US after the targeted killing of Quds Force leader Qassem Soleimani.

In a statement, a spokesperson for US Customs and Border Protection (CBP) said that, “Social media posts that CBP is detaining Iranian-Americans and refusing their entry into the US because of their country of origin are false,” and that further reports that the US government had issued a “related directive are false.”

Mr Inslee and the Council on American-Islamic Relations (CAIR) have both countered those claims, with CAIR claiming they have received information from a source with CBP notifying agents to report or detain anyone of Iranian heritage entering the US and deemed “potentially suspicious or ‘adversarial’”.

“Customs and Border Protection denials of these reports are simply not credible,” Mr Inslee said on Monday. “There are multiple firsthand accounts of CBP agents seizing people’s passports while they waited for up to 12 hours for re-entry into the United States. By all accounts, this is detention, regardless of whether the waiting area has bars on the windows.”

Further information provided to The Independent by CBP indicates the agency is operating under an enhanced threat environment as the US awaits a potential response from Iran, and that average wait times at the Blaine port of entry only briefly increased to an average of two hours late Saturday and early Sunday, in spite of accounts of people waiting between four and 12 hours.

But as reports have surfaced of the apparent detentions at the border, many have noted that the targeting of Iranian Americans is nothing new under the administration, which has frequently described the government in Tehran as one of the biggest threats to the US.

Jamal Abdi, the president of the National Iranian American Council in Washington, DC, said that the administration has been targeting Iranian Americans for three years, and that escalating tensions are likely to make things worse.

“Iranian Americans have lived in uncertainty over the 3 years since the chaos of Trump’s Muslim ban,” Mr Abdi told The Independent. “If Trump was willing to put us through that when the US and Iran had a diplomatic agreement and were on a positive track, many of us fear now that he has put the two countries on war footing.”

Among those to be stopped were a woman named Mercedes, and her two children. Mercedes, whose husband Mike spoke to The Independent but asked that their last name not be published out of concern for retribution from the Iranian or American governments, is an American citizen of Iranian descent who has lived in the Seattle area for 10 years.

Mike said that it is outrageous that the US government would stop a family of American citizens, including two kids born in the country they were returning to. His kids don’t need to be treated like that, he said, and he does not see how stopping Americans who trace their heritage to Iran, will make the United States any safer.