BRUNSWICK— Border patrol agents stopped travelers to ask about their citizenship at the Brunswick transportation station last week, a move which American Civil Liberties Union officials say “erodes basic Fourth Amendment rights.”

The stop, also known as a “hub check” is “nothing out of the ordinary,” said Michael Niezgoda, a public affairs officer for U.S. Customs and Border Protection. He would not say how often they perform these checks or when the next one may be.

“Transportation hubs are used by alien smuggling and drug trafficking organizations to move people, narcotics and contraband to interior destinations throughout the country,” according to a border patrol statement.

Due to what border patrol called “growing threats,” the agency has increased the frequency of such checks around the country to reinforce border protection. “These operations at transportation hubs serve as a vital component of the U.S. Border Patrol’s national security efforts.”

But Emma Bond, a staff attorney for the ACLU of Maine, said in an email that the checks, which she called “bus raids,” “erode basic Fourth Amendment rights to be free from unreasonable searches.”

It is important in these situations, to know your rights and inform others, Bond said.

On Sunday, border patrol agents arrested a man in Auburn during a check after he was reported to be “acting in an elusive manner and provided multiple names and dates of births to officers in order to avoid identification.”

Agents used a mobile biometric device, which uses fingerprints, facial recognition and voice recognition to identify the man as a Mexican national who entered the country illegally in 2010, and later found he had been ordered removed from the United States by a judge in 2016. A warrant for his deportation was issued in 2017, and he had allegedly been living under aliases across the country since.

Niezgoda said that during these checks, agents patrol an area and ask everyone they see for citizenship information.

“People assume they’re going to profile people, but they don’t,” he said. “They ask everyone.”

Bond, though, is not so sure.

“We are concerned that CBP agents use these transportation checks to racially profile bus passengers, targeting people based on the language they speak or the color of their skin,” she said.

Rick Smith, a resident of Camden, posted a photo of the agents in Brunswick on his Facebook page and complained of being “detained by thugs with guns and dogs. The new America.”

Smith could not be reached for comment.

Bond said the ACLU of Maine has sued the Customs and Border Protection for public records about its “invasive” immigration enforcement policies.

“Customs and border Protection is the largest law enforcement agency in the country,” she said. “We do not want to live in a show-me-your-papers society in which armed federal agents stop and question people who are simply trying to ride the bus.”