The raid was held "in co-ordination with friendly countries," the source said, adding that the 78-year-old hostage, Michel Germaneau, an aid worker kidnapped on April 19, was not found.

Spain's El Pais daily quoted diplomatic sources as saying that French special forces had participated in the dawn attack after locating the base with US help.

Al-Qaeda in the Islamic Maghreb (AQIM) set a July 27 deadline for killing Germaneau, unless its demands for a prisoner swap were met.

AQIM gave France 15 days from July 12 to arrange an exchange and said French President Nicolas Sarkozy would be responsible for the life of Germaneau, a retired engineer who had worked in the Algerian oil sector.