CATO, N.Y. (AP) — Federal agents forced open the doors of a snack bar manufacturer and took away dozens of workers in a surprise enforcement action that the plant’s co-owner called “terrifying.”

Video and photos taken at the Nutrition Bar Confectioners plant Thursday showed numerous law enforcement vehicles outside the plant and workers being escorted from the building to a Border Patrol van. Immigration agents ordered everyone to a lunchroom, where they asked for proof the workers were in the country legally, according to one 24-year-old worker who was briefly detained.

The reason for the enforcement action was unclear. Local law enforcement officials said the operation was led by U.S. Homeland Security Investigations, which did not respond to requests for information. Nutrition Bar Confectioners co-owner Lenny Schmidt said he was also in the dark about the purpose of the raid.

“There’s got to be a better way to do it,” Schmidt told The Associated Press on Friday at the family-owned business in Cato, New York, about 30 miles west of Syracuse.

The facility’s employees had all been vetted and had legal documentation, Schmidt said, adding that he would have cooperated with law enforcement if he’d been told there were concerns.

“Coming in like they did, it’s frightening for everybody — the Latinos, Hispanics that work here, and everybody else that works here as well, even myself and my family. It’s terrifying,” he said.

Cayuga County Sheriff Brian Schenck said his deputies were among those on scene Thursday morning after being asked a month ago to assist federal agencies in executing a search warrant “relative to an ongoing criminal investigation.”

He did not detail the nature of the investigation.

The lack of explanation left state Sen. Rachel May, a Democrat who represents the district, with questions.

“It’s not clear to me, if it’s a longstanding criminal investigation, why the workers would have been rounded up,” May said by phone Friday. “I feel like there are things that don’t quite add up.”

Worker describes a surprise raid

The 24-year-old worker, who spoke to The Associated Press on condition of anonymity because he feared retribution, said that after he showed the agents he is a legal U.S. resident, they wrote down his information and photographed him.

“Some of the women started to cry because their kids were at school or at day care. It was very sad to see,” said the worker, who arrived from Guatemala six years ago, then became a legal resident two years ago after working with an immigration attorney.

He said his partner lacked legal status and was among those taken away.