A US military plane crashed in rural Mississippi on Monday evening killing at least 16 people, a regional emergency management official said.
No official details were immediately available on the circumstances of the crash in northern Mississippi's LeFlore County, about 100 miles (160 km) north of Jackson, the state capital.
Captain Sarah Burns, a spokeswoman for the Marine Corps, said only that a US Marines KC-130 Hercules transport aircraft had "experienced a mishap," with news media initially reporting five confirmed deaths.
Several hours later, Fred Randle, LeFlore County director of emergency management, told Reuters that at least 16 people had perished. Randle gave no further details of the incident.
WSOC-TV in Charlotte reported, citing the Federal Aviation Administration, that the flight originated from Cherry Point, North Carolina, where a Marine Corps air base is located.
FBI spokesman Brett Carr told the New York Times
that the agency was sending officials to the scene, but authorities did not believe foul play was involved.
"We’re just trying to offer any type of assistance," Carr, a spokesman for the bureau’s Jackson, Mississippi office, told the newspaper. "It could be anything from manpower to evidence response."
Mississippi Governor Phil Bryant said in a statement on social media site Facebook that the incident was a tragedy, but provided no details.
Images posted online by news organisations showed the crumpled wreckage of a plane engulfed in flames in a field surrounded by tall vegetation, with a large plume of smoke in the sky above.
The aircraft is used for air-to-air refuelling, to carry cargo and perform tactical passenger missions. The plane is operated by three crew members and can carry 92 ground troops or 64 paratroopers, according to a description on the US Navy website.