The explosion at Accurate Energetic Systems about 50 miles (80 km) west of Nashville occurred at 7:45 a.m. local time (1245 GMT), Humphreys County Sheriff Chris Davis told a press conference.
“We do have several people at this time that’s unaccounted for,” he said, without providing precise figures. “We do have some that are deceased.”
Efforts to reach local authorities or the company were not immediately successful.
Accurate Energetic Systems develops, manufactures and stores explosives for “military, aerospace, and commercial demolition markets,” according to the company’s website. The 1,300-acre headquarters in Bucksnort, Tennessee, includes eight production buildings and a quality lab.
Hickman County Mayor Jim Bates told CNN the plant did not have a history of safety problems, although there was a small ammunition explosion there in 2014. That incident killed one person and injured three, according to the Tennessean newspaper.