The C-101 -- the same aircraft used by Spain's air force Eagle Patrol aerobatics team -- was on a training flight when it crashed near the resort of La Manga, the defence ministry said.

"All my love to the family of Captain Francisco Marin, who died in an accident in La Manga," Prime Minister Pedro Sanchez tweeted.

The defence ministry had said Marin, a flight instructor, had been "able to eject before the plane crashed in the sea".

It is unclear what the cause of the crash was, or how Marin died.

A video filmed by a witness and posted on Twitter shows a small aircraft falling at a near vertical before trying to straighten up and hurtling into the water.