By Mathieu Bonkoungou
OUAGADOUGOU (Reuters) - One Italian and two Spanish hostages freed by their al Qaeda-linked captors in Mali headed home to Europe on Thursday after an accord which mediators said involved a prisoner swap.
The three were earlier flown to a military base in the Burkina Faso capital Ouagadougou. The Burkina officer who headed the operation said two Islamists in jail in Mauritania had been released as part of a deal with Mali's MUJWA, the al Qaeda splinter group which had been holding the hostages.
The three aid workers, kidnapped in Algeria last October, were dressed all in white as they got out of a military plane after it arrived at the base in Ouagadougou.
"We would like to thank the work of Burkina people and the interest for us," Spaniard Enric Gonyalons told reporters.
Ainhoa Fernandez and Rossella Urru, an Italian national, smiled for photographers but gave no statement. The three left soon afterwards on planes heading for Italy and Spain.
"It was a release in exchange for a release," said General Gilbert Diendere, the officer who led the mission, adding that one of two Islamists freed in Mauritania had already been transferred to Mali.
He did not name the Islamists but Mauritanian media and an Islamist prisoner there said on Wednesday that Mamne Ould Oufkir, a suspect in the original kidnapping, had been freed.
The north of Mali is in the hands of local Islamist groups who first fought alongside and then outflanked Tuareg-led separatist rebels who routed government forces there in early April.
Diendere declined to comment on whether a ransom had also been paid to end the aid workers' captivity, one of a spate of hostage dramas in Africa's Sahel region.
Security experts say multi-million dollar ransom payments are usually made, though never confirmed, by authorities.
There has been no official comment from Madrid or Rome on the circumstances of the release of the aid workers, who were seized in a refugee camp near Tindouf, Algeria.
The trio's departure from the Malian region of Gao, which is in the hands of various Islamist groups linked to al Qaeda, was delayed on Wednesday by a sandstorm that prevented aircraft sent by Burkina Faso from picking them up.
"It was the most difficult mission," said Diendere. "The weather was awful and we had to sleep outside in the pouring rain before being able to take off this morning."
(Reporting by Mathieu Bonkoungou; Additional reporting by Laurent Prieur in Nouakchott; Writing by David Lewis; Editing by Myra MacDonald)