Federal prosecutors indicted five people accused of forcing 14 Mexican immigrants to work in farms in Wisconsin, where they "were victims of a severe form of human trafficking."

Prosecutors said in a grand jury indictment unsealed Tuesday that the workers had their documents seized to prevent travel and were shielded from detection by being hidden "in buildings and other places." They were forced to work under the threat of being caused "serious harm," the indictment read.

The workers were sometimes denied water during hot days, worked 12-hour shifts six or seven days a week with only 30-minute lunch breaks, and were denied medical care or punished when they sought it out themselves, according to a document prosecutors filed to support the defendants' detention.

The indictment alleges the defendants recruited the immigrants, all Mexican men, and got them agriculture work visas under the pretense they would work in Georgia. Instead, prosecutors say the defendants brought them to Wisconsin farms, where they worked from July 2016 to Nov. 10, 2016.

The indicted are: Saul Garcia, 49, Saul Garcia, Jr., 26, Daniel Garcia, 28, Consuelo Garcia, 45, and Maria Remedios Garcia-Olalde, 52. They face several charges, including forced labor, trafficking in peonage, slavery, and involuntary servitude. One of the men is also accused of trying to influence the testimony of two of the victims to the grand jury.

The defendants are in custody and don't yet have attorneys.

While working in Wisconsin farms in Kenosha and Racine, prosecutors said the workers were cramped into a hotel, often four men to a room, and sometimes had to sleep on the floor. Beginning at 6 a.m., four yellow school buses would take them to work, according to prosecutors.

Although the charges were filed on behalf of 14 men in Wisconsin, in 2015 and 2016 the defendants brought hundreds of Mexican immigrants to work on their farm in Georgia, where the suspects live, according to prosecutors in that state. Some of the workers were eventually sent to Wisconsin.

Authorities busted the Wisconsin operation on Nov. 10, 2016, when they stopped one of the yellow school buses. Of the 23 workers on the bus that day, 11 returned to Mexico and 12 chose to stay in Wisconsin. The indictment doesn't say where in Mexico the men were recruited and the victims are not named.

"Trafficking another human being is a particularly vile crime," Wisconsin U.S. Attorney Matthew Krueger said in a statement. "The Department of Justice is committed to prosecuting anyone who seeks to sell another person's freedom."

As part of their prosecution, the federal government is attempting to seize 15 properties the defendants have in Georgia, as well as 15 of their vehicles registered in the state.