NOUAKCHOTT:  Mauritanian troops attacked the base of an Al-Qaeda affiliate, killing several "terrorists," a Mauritanian official said Friday, without confirming whether the move sought to free a French hostage.

"The operation which targeted a terrorist base is complete," the source said.

"Several armed terrorists were killed and wounded at the base, located in the desert, which serves as a refuge for terrorist fighters from the nebulous Al-Qaeda in the Islamic Maghreb," or AQIM.

The source did not specify whether the raid was aimed at liberating 78-year-old Michel Germaneau, an aid worker kidnapped on April 19 now facing execution.

But a Malian source who has mediated talks to release several Westerners kidnapped in the region told AFP that "the Mauritanians went to the Sahara where the French hostage was being held. It seems they went to find him but he could not be located."

The source could not confirm whether troops from former colonial power France were involved in the operation, but said Mauritanian troops were present.

"France was aware of the operation before it kicked off. Now the question is the degree of its involvement," the source added.

Spanish newspapers El Pais and ABC meanwhile said on their websites that a French military operation to free Germaneau failed early Thursday.

Six suspected extremists were killed and others fled the undisclosed scene, possibly in Mali, during the operation, the papers reported, quoting diplomatic sources.

In Paris, French foreign ministry spokesman Bernard Valero refused to comment, simply saying: "Since the start, we have been fully mobilised to try and free our compatriot. We are also very worried because we have tried to establish contact with the kidnappers but they have spurned us up till now."

AQIM members have threatened to kill the French hostage. On July 11, they gave France a 15-day deadline to help secure the release of its members in the region, warning that Germaneau would be executed if Paris failed to comply.

France is the former colonial ruler of several countries in the region, including Mali, Mauritania, Algeria and Burkina Faso.

Germaneau was kidnapped in northern Niger in April, when he was working with the Enmilal aid group to improve health services and schools in the impoverished Sahel country.

Officials in France and Niger believe he is being held in Mali.

The French foreign ministry said it had received no demands from Germaneau`s kidnappers but took their threat to kill him seriously.

AQIM killed British tourist Edwin Dyer last year after holding him captive for six months when London refused to yield to the Islamists` demands to free jailed Muslim cleric Abu Qatada, once regarded as Osama bin Laden`s right-hand man in Europe.

It is also holding two Spaniards in the region after kidnapping them more than seven months ago: Albert Vilalta, 35, and 50-year-old Roque Pascual.

BDST: 10:04 HRS, July 23, 2010

NJ