SEATTLE (AP) — U.S. Customs and Border Protection Acting Commissioner Mark Morgan said Tuesday that border officials in Washington state “got a little overzealous” when they detained Iranian and Iranian-American travelers at the U.S.-Canada border last month.

As many as 200 people of Iranian descent were held up for as long as 12 hours as they crossed the border from Canada into Washington state the weekend of Jan. 5-6, following a U.S. drone strike that killed a top Iranian general.

Many of those detained were U.S. citizens. Some had even been cleared to participate in a program for trusted travelers.

The federal agency said at the time it had not targeted Iranian Americans based on their country of origin or issued any such directive to its officers.

But an immigration attorney in Blaine, Washington, obtained a copy of a directive apparently issued by the agency’s Seattle field office that said agents should “conduct vetting” on Iranian, Lebanese and Palestinian nationals born between 1961 and 2001. It also said anyone else who had traveled to Iran or Lebanon should be screened.

Without mentioning anyone by name, Morgan told a news conference in Washington, D.C., on Tuesday that officials in the region imposed additional security screening on people from Iran following the drone strike.

The agency does not target people based on nationality, and there was no agency-wide directive to do so, Morgan said Tuesday.

“In that one instance, leadership just got a little overzealous, and we corrected that right away,” he said.

Border agents typically have discretion to refer a traveler for additional inspection, such as when their paperwork is not in order or if something raises the agent’s suspicion.

But immigrant rights groups and lawmakers, including U.S. Rep. Pramila Jayapal, a Seattle Democrat, said singling out Iranian Americans absent such factors was wrong and violated their right to equal protection under the law.