RNA - The US Customs and Border Control (CBP) detained at length and questioned the Iranians who were returning to the US after attending a concert on Saturday in the Canadian city of Vancouver, the CAIR said.
Other Iranians, who have been residing in the United States for years, were denied entry to the US.
"Many more are turned around at the border and refused the opportunity to enter the United States due to a lack of capacity for Customs and Border Patrol to detain them," CAIR's Washington chapter said in a joint news release with Hoda Katebi, a community organizer and fashion blogger.
In a tweet, Washington Congresswoman Pramila Jayapal said she was "deeply disturbed" by the reports of the detentions.
"This is a HUGE DEAL. Iranians who have been born and raised in the USA are literally being ILLEGALLY DETAINED for 11+ hours for NO REASON & interrogated with intrusive and inappropriate questions about political opinions, what courses they or their parents studied in college," Katebi said in a tweet.
CAIR noted that the Department of Homeland Security (DHS) had issued a national order to CBP to "report" and detain anyone with Iranian heritage entering the US who was deemed potentially suspicious, regardless of their citizenship status.
CBP denied that it was detaining individuals because of their country of origin.
"Social media posts that CBP is detaining Iranian-Americans and refusing their entry into the US because of their country of origin are false. Reports that DHS/CBP has issued a related directive are also false," CBP spokesperson Michael Friel told Middle East Eye in an email.
Masih Fouladi, the executive director of CAIR Washington, said the reports of detentions "are extremely troubling and potentially constitute illegal detentions of United States citizens."
Mana Mostatabi, communications director at the National Iranian American Council (NIAC), told Middle East Eye news portal that potentially as many as 150 individuals have been detained, with some being held for 11-16 hours.
Citing an initial research conducted by NIAC, Mostatabi said those detained were asked about their relatives, occupations, birthdays, the last time they visited Iran and their opinions on current tensions.
"The common denominator is Iranian heritage, which should raise immediate concerns of discriminatory and illegal actions targeting on the basis of national origin," Mostatabi said.
Mostatabi added that there were additional unconfirmed reports of detentions at San Francisco Airport and Los Angeles International Airport.
The detentions come amid growing tensions between the US and Iran, especially after Washington assassinated a top Iranian commander in an airstrike in the Iraqi capital of Baghdad on Friday.
The attack targeted General Qassem Soleimani, the commander of Iran's Quds Force, and Abu Mahdi al-Muhandis, the second-in-command of Iraq’s Popular Mobilization Units (PMU), as well as eight companions of the pair.
Iran has pledged a “harsh revenge” to the assassination, prompting US President Donald Trump to hit 52 sites in the ancient country, including places important to the Iranian culture.
On Saturday, anti-war protesters rallied across the US capital as well as about 70 other US cities to denounce Trump's warmongering.