Law enforcement and other emergency personnel including firefighters arrived on location at the school on Friday morning about an hour-and-a-half before the school bell rang, local television reported.
Pender County Sheriff's Office Captain James Rowell initially told reporters that no injuries were been reported as of 7:04 am local time, and that the call about the possible active shooter in the school came in around 6:30 am. Shortly after 8 am, Rowell said that police were continuing sweeping through the building as a precaution, but that the incident appeared to be a false alarm.
Topsail High School is located in the Town of Hampstead, about 175 km southeast of North Carolina capital Raleigh. The school already faced a code red lockdown in late May. In that incident, two students were charged with bringing weapons, including a semi-automatic gun and knives to the school, with one of the boys claiming he brought a semi-automatic rifle to school to stop a rumoured school shooter.
The US has suffered over three hundred school shootings since January 1.