Multiple people have been killed in an blast at an explosives manufacturing plant.

The "massive" explosion took place at Accurate Energetic Systems near Bucksnort, Tennessee just before 8am, local outlets reported.

At least 19 are missing and multiple others have been hospitalized, according to Humphrey County Emergency Management officials.

A statement put out by Humphreys County urged people to avoid speculation and respect the privacy of the victims.

Multiple people dead and more missing after major explosion in Tennessee

Humphreys County Sheriff Chris Davis confirmed to reporters there are "some" fatalities and several people missing in the blast, though he did not give specific numbers.

Mr Davis told a press briefing: "We got a very big investigation.

"This is not going to be something that we're going to be like a car wreck or something like that, that we're just going to clean up the debris and leave. We're going to probably be here for a few days."

"We're trying to take as much time as is needed right now. We're prioritizing people that are involved, their families and trying to be very compassionate toward them."

Meriwether Lewis Electric Cooperative customers in the area are reporting power outages since the time of the explosion.

It stated: "MLEC is aware of a serious incident in the Bucksnort area that has caused power and broadband outages for some members.

"Our crews are working closely with emergency officials to restore service as safely as possible.

"Our thoughts and prayers are with those impacted, and we ask everyone to avoid the area as emergency responders work. We’ll provide updates on our progress as the day continues."

The facility is located in wooded hills near Bucksnort, around 60 miles southwest of Nashville

Emergency crews were initially unable to enter the plant because of continuing detonations, Hickman County Advanced EMT David Stewart told reporters by phone.

Officials said the main concern at this time is the possibility of a secondary explosion.