Multiple people were dead or missing after a massive blast rocked a US explosives factory on Friday, sending emergency responders rushing to the site and prompting official warnings for the public to avoid the area, authorities said.

“We can confirm there has been an explosion at Accurate Energetic Systems in the Bucksnort area,” located in Hickman County, Tennessee, the local sheriff’s office wrote on Facebook.

“Emergency services are currently on the scene working to address the situation,” it added.

The mayor’s office in Hickman County told AFP that it could not immediately confirm any fatalities or the cause of the explosion.

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.

However, Humphreys County Sheriff Chris Davis reported “some” fatalities and added that several people were missing in the “very devastating blast” that engulfed an entire building at the facility.

“We do have several people at this time that’s unaccounted for. We are trying to be mindful of families and that situation,” Davis said. “We do have some that are deceased. But we’re going to go back and, like I say, talk to these families, notify these families.”

Davis said authorities had secured the area, but warned of the possibility of smaller explosions around the site.

Accurate Energetic Systems, an explosives manufacturer founded in 1980, 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.

It did not immediately respond to AFP’s request for comment.