TOWNER (AP) - Immigration officials say 13 employees at a dairy here have been arrested on charges of being in the country illegally. A government spokesman and U.S. Attorney Drew Wrigley denied the dairy operator's allegations that officers used unnecessary force.

Mike Zimmerman, who operates the Sandhills Dairy, estimated about 50 officers were on the scene Tuesday. He said they displayed weapons, kicked down doors and handcuffed his son and employees. Officers also handcuffed a longtime friend of his, held a gun to his head and asked for his birth certificate, Zimmerman said.

"It's an unbelievable, frustrating and humiliating experience," Zimmerman said of the raid.

Wrigley and Tim Counts, a spokesman for federal Immigration and Customs Enforcement agency, said Wednesday that officers did not hold a gun to anyone's head.

"That is a preposterous allegation and that's false," Counts said. The officers "acted with professionalism and fully within the law," he said.

Wrigley said Zimmerman was "throwing around baseless claims that are completely false."

"Not a single individual received so much as a scratch," he said.

Counts said 36 officers were on the scene, including Border Patrol agents and agents from the state Bureau of Criminal Investigation, the McHenry County sheriff's office and the Highway Patrol. He said Zimmerman's son was "briefly handcuffed because he was uncooperative and belligerent," but quickly calmed down.

Wrigley said officers did have to force their way into some buildings on the dairy farm but that they did so professionally.

"That is not only their right when armed with a federal search warrant. It is their obligation to search and secure the premises," he said.

Those arrested Tuesday included 12 men and one woman, Counts said. One of the workers is from Guatemala and the rest are from Mexico, he said.

Officers took the group to the Border Patrol station in Bottineau. Wrigley said officials will be deciding whether to schedule the workers for deportation hearings or charge them with crimes.

The woman was released for "child care issues" but still must appear at a hearing, Counts said. Wrigley said the woman has a 1-year-old child who needs her care.

Zimmerman said he believed the workers' paperwork was in order when they were hired. He said the agents arrived about 8 a.m. Tuesday, to block traffic in and out of the dairy and halt milking operations.

Wrigley declined comment on whether Zimmerman might face charges, citing the ongoing investigation. He said the probe has been going on "for quite some time," though he would not say how long or how it initially came about.

Counts said the officers had a search warrant based on leads in the ongoing investigation, but he also declined to discuss details of the case.

"It's important to remember that ICE and its law enforcement partners were executing a federal criminal search warrant issued by a federal magistrate judge," he said.

Zimmerman said the dairy milks 700 cows three times a day and the raid left him short of workers. He said he may have to start selling off his herd.

Zimmerman said Wednesday that volunteers from the area were helping feed and milk the cows.

"This place just never stops," he said.