Updated

Two Ohio residents have been indicted on federal charges of distributing heroin laced with carfentanil (kahr-FEHN'-tuh-nihl), a substance used to tranquilize large animals that authorities say is 10,000 times more powerful than morphine.

Federal, state and local officials say the seven-count indictment announced Wednesday alleges 31-year-old Phillip Watkins and 26-year-old Jeanetta Crawford conspired in August to sell heroin laced with carfentanil from their Cincinnati home. The indictment also charges them with operating drug-involved premises. Authorities allege the drugs caused serious physical harm, including nonfatal overdoses.

Watkins and Crawford were arrested Sept. 15 and have been ordered held without bond.

Watkins' attorney Scott Rubenstein said Thursday that it's too early in the case to comment. Crawford's attorney didn't immediately return a call seeking comment on her behalf.