HAMPSTEAD, N.C. — Authorities in North Carolina said a reported active shooter at a high school was actually a malfunctioning water heater.

Pender County Emergency Director Tom Collins told WECT-TV on Friday that a malfunctioning water heater at Topsail High School was believed to cause a gunfire noise that led to reports of an active shooter.

Capt. James Rowell with the Pender County Sheriff's Office said there were no immediate reports of injuries Friday.

Pender County Schools said it was "taking all precautions" and its campuses on the eastern side of the county were on lockdown. It told staff at Topsail Elementary, Topsail Middle and Topsail High to report to Lowe's Foods in a tweet.

Pender Schools also told parents not to drive their children to school yet, as the schools were on lockdown.

Reports of an active shooter came in around 6:30 a.m. According to Topsail High School's website, school begins at 8:30 a.m.

Topsail High School is located near the coast in Hampstead, about 20 miles north of Wilmington. It has around 1,300 students enrolled.

In May, an 18-year-old student was found in the school's parking lot with a large knife strapped to his leg and three other knives. A 16-year-old boy who authorities say armed himself with a semi-automatic rifle after hearing about that potential attack also was arrested.