An Al Qaeda offshoot in North Africa says it released a Spanish woman who spent 100 days as a hostage in Mauritania because she voluntarily converted to Islam.

In a statement posted on militant Web sites Friday, Al Qaeda in the Islamic Maghreb says Alicia Gamez adopted the Muslim name Aicha after being exposed to the teachings of Islam by her captors.

She and two male colleagues still being held captive worked as volunteers for an aid group called Barcelona Accion Solidaria. They were kidnapped by gunmen Nov. 29 while delivering relief material to poor villages. Gamez returned home Wednesday.

A photo with the statement showed three armed men standing behind Gamez and the other hostages. Gamez appears in the photo wearing a head scarf.