Rana Rahimpour, a British-Iranian journalist with BBC, was prevented Tuesday from flying to the United States because of her dual nationality. U.S. officials told Rahimpour that she could not travel to the country under a visa waiver program, in which dual citizens from various countries are required to apply for a U.S. visa.

Rahimpour, who works for BBC’s Persian-language service in London, was stopped at Heathrow airport ahead of her New Jersey flight. The 33-year-old said that no authorities at the U.S. embassy in London seemed to know if the new law was brought into effect.

According to the U.K foreign office website, the rule will come in on April 1. However, the U.S. Department of State website stated that officials have “begun the process of implementing changes” to the waiver program, enacted on Dec. 18, 2015. Two of Rahimpour’s cousins were also stopped from flying to the U.S. They all were travelling to a family birthday in the country, BBC reported.

Rahimpour said the new law, which also affects Iraqi, Syrian and Sudanese people, was confusing and even her contacts in Washington were not aware about the kind of changes being made to it. She added that the legislation treated Iranians unfairly.

“I expect the U.S. to see a difference between ordinary Iranians and politics, and what’s interesting, it comes only three days after lifting sanctions,” she said, according to the Guardian. “Iranians feel they are being treated very unjustly and over the last few weeks. They have said that there has never been a terrorist attack by an Iranian national on American soil. This is very unfair, they referred to the nationality of those involved in 9/11 and you can’t find any Iranians involved,” Rahimpour added.

The U.S. visa waiver was brought in amid security concerns after the deadly Paris attacks in November 2015.