Los Angeles: A US Air Force B-52 Stratofortress crashed shortly after takeoff from Edwards Air Force Base in California's Mojave Desert, the base said. 

The crash occurred on Monday at approximately 11:20 a.m. local time, the base wrote on X.

Emergency response teams were immediately dispatched to the scene, and response operations remain ongoing.

In a separate post on X, the military base announced that the airfield was closed and all inbound aircraft were being diverted, Xinhua news agency reported.

"Today, Edwards Air Force Base experienced a terrible tragedy, and we lost eight great Americans," Col James Hayes told reporters, describing them as a "mixed crew of military, government civilians and government contractors".

All non-commercial visitor passes were suspended until further notice to allow the installation to focus entirely on emergency response operations, the base said.

B-52 Stratofortress was carrying eight people and crashed shortly after takeoff from Edwards Air Force Base, with no survivors reported, the base said.

The aircraft was on a routine test mission, the base said on X. The crash sent a huge plume of black smoke into the air that could be seen for miles.

"Initial indications are that the crash was not survivable," the base said.

Officials are working to account for all personnel involved. The cause of the crash remains under investigation.

The B-52 is a long-range strategic bomber that has been participating in bombing raids on Iran during the latest US-Israeli war on the country.

Capable of flying at up to 50,000 feet (commercial airliners fly around 35,000 feet) the colossal bomber's 70,000lb payload can include hundreds of conventional bombs and 32 nuclear cruise missiles.