Two people have been charged with holding six mentally ill patients at group homes and making them work against their will, authorities said.

A man and a woman were arrested Tuesday under a federal law banning involuntary servitude (search) after 20 FBI agents searched two group homes in Newton, Kan.

The agents rescued four adults from one home and two from the other, FBI spokesman Jeff Lanza said. The identities of the two people who were arrested were not immediately released.

The six mentally ill individuals had lived in the homes for "a long period of time," Lanza said. It was not immediately clear what type of work they had been forced to perform.

Authorities provided few details. The complaint and an affidavit were under court seal in Wichita. The charges were to be unsealed Wednesday.

Violators of the servitude law can be sentenced to up to 20 years in prison, unless their actions involve kidnapping, sexual abuse or an attempt to kill, in which case life in prison is possible.

The group home residents were placed in the care of Kansas social service workers, Lanza said.