TORONTO -- Dozens of Canadians and Americans of Iranian descent say they were held and interrogated at a U.S. border crossing in B.C. over the weekend as tensions between Iran and the U.S. heat up.

According to the Council on American-Islamic Relations (CAIR), more than 60 Iranian nationals and American citizens were held at the Peace Arch border linking B.C. to Washington state after attending an Iranian pop concert in Vancouver.

Among those reportedly held for questioning included Iranian-Canadians.

Sam Sadr, an Iranian-Canadian who travelled to the U.S. using his Canadian passport, says he was held at the border for eight hours, during which time he saw dozens of other Iranians held, including children.

“This is the first time I put my feet in the U.S. I told the border person this is very [shocking] and called discrimination,” Sadr told CTV News Channel Monday.

Len Saunders, a Blaine, Wash.-based immigration lawyer, witnessed what he described as “chaos” at the border crossing first-hand. Speaking to CTVNews.ca by phone from Washington state, Saunders said there were so many people waiting to speak to officials, they were given foodbecause of the delays. He says two of his clients were held by border agents.

“One recently became an American citizen and they were taken into secondary and questioned for four to five hours with regards to their family ties to Iran; parents’ information; siblings’ information; what they do for work; and when they travelled there,” Saunders said during an interview on CTV News Channel Monday.

“It was basically a dragnet of anyone who was born in Iran coming through the local port of entry over the weekend.”

What concerns Saunders most is his client's claims that when she volunteered to withdraw her application for entry, she was told she was not allowed to leave.

“It’s troubling,” he said by phone. “Usually you’d think if you knock on the door of someone’s house you can leave whenever you want, but they weren’t letting them leave.”

CAIR claims that those detained had their passports confiscated and were questioned about their political views and allegiances.

The organization also claims to have information from a source at U.S. Customs and Border Patrol (CBP) that said the Department of Homeland Security (DHS) had issued a national order to report and detain anyone with Iranian ties.

On Sunday, CBP denied that it had ordered the detention of Iranian nationals.

“Social media posts that CBP is detaining Iranian-Americans and refusing their entry into the U.S. because of their country of origin are false. Reports that DHS/CBP has issued a related directive are also false,” the agency said in a tweet.

But Robert McCaw, Director of Government Affairs at CAIR, says those words may be a smokescreen.

“While they say no one was detained, people were held for up to 10 to 12 hours in secondary screening and, again, interrogated,” McCaw told CTV News Channel.

“If you’re held for more than 10 to 12 hours and interrogated by federal law enforcement, I would call that detention.”

Saunders says the detentions were particularly problematic for U.S. citizens.

“As an American citizen, you have the right to enter the country and not be interrogated for many hours,” he said.

“This is something I’ve never seen. I’ve been practising in northern Washington state for over 20 years; I’ve never seen one country’s individuals taken in and questioned for such lengthy periods of time.”

He notes that Iranian-Canadians would have no legal recourse if they were to be detained at the border.

“You have no right to enter the U.S. [without a U.S. passport],” he told CTVNews.ca.

He notes that anyone attempting to cross into a foreign country has the right to withdraw their application for entry and return to their home country at any time during the immigration process.

However, he worries that U.S. immigration officials may have been given different orders.

Saunders notes that he did not hear of issues atany other Canadian-American land border crossings over the weekend.

“It seems to be a local phenomenon which makes it even worse,” he said.

Michael Friel, a spokesman for CBP, told the Associated Press that border wait times increased Saturday at the Washington border crossing because of “increased traffic and reduced staffing” over the holiday season.