A drone crashed at an Arizona prison in September, and officials found drugs and cellphones aboard the vehicle, The Arizona Republic reported.

The drone crashed in a yard accessible only to corrections officers. The Arizona Department of Corrections said Thursday it is still trying to determine who was behind the delivery Sept. 24 delivery.

It was the first known incident involving a drone at an Arizona state prison, corrections spokesman Andrew Wilder told the Republic.

The drone flew over Arizona State Prison Complex-Lewis in Buckeye, Wilder said. The contraband had been tied up in an orange sweatshirt. Inside were two cellphones and several freezer bags filled with marijuana, images show.

The items were sent to the state crime lab for fingerprint and DNA analysis, but investigators have not been able to locate the origin of the drone, Wilder said.

All airspace around prisons is federally restricted, so flying any item, including drones, near the facilities is prohibited, Wilder said. Attempting to smuggle drugs and cellphones into prisons is a felony.