The explosion happened at the General Dynamics Ordnance and Tactical Systems' plant in Camden, about 86 miles (138 km) south of Little Rock, the capital of Arkansas on Wednesday, a company spokesperson said, reported Xinhua news agency.

The company confirmed the explosion after initially calling it an "incident involving pyrotechnics."

"At this time, we are working with first responders and can confirm the incident resulted in at least two injuries and one missing individual," General Dynamics said in a statement, adding that it's cooperating with the authorities in the investigation.

The company also confirmed the production pause at the building where the explosion occurred.