MANILA, Philippines —  They display the accouterments of revolution: Zapatista-like masks, Afghan-style rolled cloth hats, dark sunglasses, a clenched-fist salute and big guns.

They are fighting the Philippine army in the desperately poor region of Mindanao, where Muslim rebels have struggled for a generation for a separate Islamic state. 

But the demands of Abu Sayyaf — Father of the Sword — veer between the high-minded and the purely lucrative. Some critics question whether they are even Islamic separatists or merely bandits. 

The lines blur in Mindanao, a region with a third of the Philippines' land mass and about a quarter of its population where rebellion frequently grows more from a sense of dispossession than from strict Islamic ideology. 

The Muslims in Mindanao take pride in their centuries of resistance to Spanish and then American colonial rule of the heavily Roman Catholic Philippines. 

They live in the poorest part of a poor country, and the creation of a Muslim semiautonomous region almost a decade ago has provided few benefits. 

In the face of discrimination and economic pressure caused by Christians moving into the region, some have adopted Spain's term for Muslims, calling themselves Moros, or Moors. 

The largest guerrilla group, the Moro National Liberation Front, signed a peace treaty with the government in 1996, and its leader is now governor of the semiautonomous region. But two others, the Moro Islamic Liberation Front and Abu Sayyaf, are still out in the hills. 

The Moro Islamic Liberation Front walked out of peace talks in April, 2000 after the army began air and ground attacks on rebels holding a Mindanao highway near their headquarters. Fighting and bomb attacks continue. 

The smaller and more extreme Abu Sayyaf is notorious for its brutality. 

Its rebels beheaded two Filipino hostages as a "birthday present" for President Joseph Estrada in April, 2000. Wounded soldiers have been decapitated or had their eyes gouged out. 

There are reports that a slain female hostage's breasts were cut off. Rebels have attacked churches and kidnapped and killed foreign missionaries. They are blamed for a 1995 attack on a town that killed 53 people and injured 100 others. 

Abu Sayyaf emerged in 1991 as an offshoot of a group founded in 1972 by Iranian fundamentalists. 

It took the nickname of founder Abdurajak Abubakar Janjalani, a former Moro National Liberation Front member who studied Islam in Libya, Syria and Saudi Arabia and fought in Afghanistan. He was killed in a clash with police in late 1998. 

The group, already weakened by casualties and defections, deteriorated further as members jousted to succeed him. Ultimately his brother Khadaffy took control. 

The Philippine military says Abu Sayyaf has links to wealthy Saudi exile Osama bin Laden, accused by the United States of planning the 1998 bombing of two U.S. embassies in Africa. They have demanded the release of Ramzi Yousef, the mastermind of the 1993 New York World Trade Center bombing. 

The group gained world attention when it snatched 21 people from a Malaysian diving resort on April 23, 2000 and took them to the Philippine island of Jolo, about an hour's boat ride away. 

They are also holding about eight Filipinos in nearby Basilan, mostly children. That group is all that remains of about 50 hostages taken from schools on March 20. The captives' ranks were thinned by killings, rescues and releases. 

The Jolo hostages included three Germans, two French, two South Africans, two Finns, a Lebanese, nine Malaysians and two Filipinos. Their plight drew a top European Union diplomat and a Libyan envoy to the Philippines to successfully negotiate for their release. 

Libyan leader Moammar Qaddafi earned unprecedented international thanks for persuading Filipino rebels to release the hostages taken from the Malaysian resort. 

Hours after their release, however, a radio station in the southern Philippines quoted rebel spokesman Abu Sabaya as saying the group had abducted Jeffrey Craig Edwards Schilling, an American. Philippine negotiators confirmed the abduction and U.S. officials were en route to investigate.