Al-Qaeda in the Islamic Maghreb released two Spaniards who spent nearly nine months in captivity after "some of our requests" were met, the North African branch of the group said in a statement quoted by the daily El Pais on Tuesday.
Sources close to Burkina Faso negotiators who mediated in the deal earlier said Spain may have paid up to 7 million dollars for Albert Vilalta and Roque Pascual, who arrived in Barcelona overnight, DPA reported.
There was also speculation that their release was linked to an alleged deal between Mali and Mauritania to release an al-Qaeda collaborator whom a Mauritanian court had sentenced to 12 years in prison for organizing the kidnapping.
Vilalta and Pascual were abducted in Mauritania on November 29 with a woman, Alicia Gamez, and taken to northern Mali. Gamez was released in March.
The way Spain had dealt with the case of Pascual and Vilalta was "a lesson for the French secret services," al-Qaeda said in an apparent reference to French hostage Michel Germaneau, who was killed in July.
Al-Qaeda then announced it killed Germaneau in retaliation for a French-supported raid by the Mauritanian military in northern Mali.
Pascual and Vilalta flew to Barcelona from the Burkina Faso capital Ouagadougou on board a Spanish air force plane.
The two, who spent 268 days in captivity, were the hostages held the longest so far by al-Qaeda in the Sahel region.