The insurgency in the Philippines' impoverished southern region of Mindanao has killed more than 120,000 people in three decades. The main players include:

Abu Sayyaf: Radical band thought to have about 200 fighters and little public support. Now holding two groups of hostages. Splintered from the main rebel group, the Moro National Liberation Front, in 1991. 

Moro National Liberation Front: Signed a peace treaty with the government in 1996 after more than 20 years of fighting. Leader Nur Misuari is now governor of a four-province Muslim semiautonomous area on Mindanao, the Philippines' second-largest island. 

Moro Islamic Liberation Front: Larger of the two groups still fighting. Split from the Moro National Liberation Front in 1978. Leaders include Islamic scholars. Walked out of peace talks with the government late in April, after the army began air and ground attacks on rebels holding a Mindanao highway near their headquarters. 

New People's Army: Communist rebels who ended peace talks with the government a year ago. Have been fighting for 31 years.