RALEIGH, N.C. (AP) - Authorities say a malfunction caused public warning sirens to be heard near a North Carolina nuclear power plant.

North Carolina's Department of Public Safety said Friday afternoon on Twitter that the sirens that went off around 1 p.m. were a false alarm. Authorities said there was no emergency at the Harris Nuclear Plant southwest of Raleigh.

Duke Energy said that a malfunction caused the sirens to go off and that the cause is being investigated.

There is a system of warning sirens in a 10-mile radius around the plant.