SALT LAKE CITY (AP) — Federal labor authorities say a concrete company owned by members of a polygamous group is putting underage laborers to work for long hours in hazardous conditions with little pay on job sites around the country.

U.S. Department of Labor lawyers say in a case filed Tuesday that Utah-based Phaze Concrete put at least two boys ages 12 and 14 to work on job sites during school hours.

Investigators said they believe the company has pulled more teens from the group’s home base along the Utah-Arizona border during the last decade. Prosecutors say Phaze used child labor on jobs for companies like Scheels All Sports in Kansas, Wal-Mart in Missouri and Hobby Lobby in Nebraska.

Those companies did not immediately return messages seeking comment. A lawyer for Phaze, Blake Hamilton, said Wednesday the company hasn’t yet been served with the lawsuit and he couldn’t comment on the allegations.