Two US military aircraft crashed within 24 hours, including a fatal B-52 accident in California and an F/A-18 crash in Washington.

Edwards Air Force Base said emergency responders were on the scene.

A military aircraft crashed at a base north of Los Angeles Monday morning, Edwards Air Force Base said on social media.

An official said an investigation could take up to six months and noted the B-52 in question was involved in a "radar modernization program."