What is the Abu Sayyaf?
The Abu Sayyaf, whose name means "Father of the Sword," is the more militant and smaller of two organizations fighting for an Islamic state in the southern Philippines. Analysts and diplomats say the Abu Sayaff's primary motivation is the money it obtains from kidnappings. The larger group, the Moro Islamic Liberation Front, is suspected to be behind recent bombings.

Five Detained in Philippine Bombing (March 6, 2003)

From the State Department: List of Foreign Terrorist Organizations