Ohio officials are investigating after a drone dropped a package full of illegal drugs into a prison yard, sparking a fight over the contraband.
The package was delivered to Mansfield Correctional Institution – a prison about 65 miles (110km)southwest of Cleveland- on 29 July, officials said.
The box contained small amounts of marijuana, heroin and tobacco.
More than 100 inmates were in the prison yard when the fight broke out, but no inmates or staff were hurt.
Nine prisoners who were involved in the fight were placed in solitary confinement.
JoEllen Smith, a spokeswoman for the Ohio Department of Rehabilitation and Correction, said this is the latest in series of attempts to deliver prison contraband via drones.
Ms Smith said the agency is taking steps to stop drones before they enter the grounds of prisons.