A United States Air Force B-52 Stratofortress has crashed shortly after taking off from Edwards Air Force Base in the state of California.

"A United States Air Force B-52 Stratofortress crashed shortly after takeoff on the Edwards airfield at 11:20 am," the base said X.

"Emergency crews immediately responded to the scene and the situation is ongoing."

The aircraft went down in Kern County, California, according to officials.

The base later announced the closure of the airfield, with all inbound aircraft being diverted.

"All non-commercial visitor passes have been suspended until further notice to allow the installation to focus entirely on emergency response operations," it added.

Photos from the scene showed a plume of smoke rising near the wreckage.

Status of crew remains unclear

Edwards Air Force Base, California, and Air Force Pentagon headquarters referred questions to the initial announcement of the crash and declined to provide additional details.

"More information will be provided as it becomes available," the base added.

The B-52 typically operates with a crew of five, including two pilots, a radar navigator, navigator and electronic warfare officer.

The status of those on board was not immediately known.

The aircraft is one of 76 B-52s remaining in the Air Force inventory. The fleet is expected to remain in service for decades as the Air Force pursues extensive modernisation upgrades.

The nuclear-capable bomber first entered service in the 1950s and remains a central component of the US strategic bomber force.