A pilot and passenger in one of the planes had been declared dead. (Representational)

Two British light aircraft collided mid-air after taking off from an airstrip in the southern French Alps on Wednesday, killing two fliers while a third survived the accident, local authorities said.

A pilot and passenger in one of the planes had been declared dead, a statement from the local government office in the village of Digne-les-Bains said, adding that they were aged 37 and 18 and were both British.

The pilot of the second plane, who was also British, survived the crash with light injuries after the collision close to the Italian border.

The aircraft had taken off earlier from the Barcelonnette-Saint-Pons airstrip in Alpes-de-Haute-Provence region in southern France.

French emergency services backed by a police helicopter were at the scene, while an investigation has been opened to determine the cause of the accident, the statement added.