FACTBOX: Philippine rebel group Abu Sayyaf

(Reuters) - The Philippines said two U.S. soldiers and one Filipino marine were killed in a land mine attack on a southern island that is a stronghold of the Abu Sayyaf, one of the smallest but deadliest Islamist militant groups in the country.

Following are some facts about the group, which is on the U.S. State Department's blacklist for the abduction and murder of tourists, including Americans:

- The Abu Sayyaf, which translates as "Bearer of the Sword," was formed in the 1990s by a charismatic Islamic preacher who returned to the Philippines from Afghanistan after the armies of the former Soviet Union were driven out of the country in 1989.

- The Abu Sayyaf wants an independent Islamic nation in the south of the mainly Roman Catholic Philippines, aligning itself with militants who espouse a similar vision of a pan-Islamic super-state in Southeast Asia. It has been linked to al Qaeda and to Jemaah Islamiah.

- The founder and leader of the Abu Sayyaf, Abdurajak Abubakar Janjalani, was killed in December 1998 in a gunbattle with police and was replaced six months later by his younger brother, Khaddafy Janjalani. Another brother, Hector, is in jail for murder and kidnapping.

- Khaddafy was killed in a clash with soldiers in late 2006.

- Yasser Igasan, a foreign-trained Islamic preacher, is believed to have replaced Khaddafy Janjalani, according to army intelligence. But, the loosely structured Abu Sayyaf also has a nine-member "shura" (council) that makes key decisions.

- Based on the Basilan and Jolo islands off the larger island of Mindanao, it began with small attacks, targeting Roman Catholic churches, missionaries and nuns, but soon graduated to larger-scale assaults as well as high-profile kidnappings of foreigners, including abducting tourists from a Malaysian resort island in 2000.

- A year later it kidnapped tourists and workers from a resort in the western Philippines. Most were released on payment of ransom, but three victims, including an American, were beheaded.

- The group was blamed for the country's most deadly militant attack, the bombing of a ferry near Manila Bay in February 2004 that killed more than 100 people.

- In January this year, members of the group kidnapped three officers of the International Committee of the Red Cross who were inspecting a prison on Jolo. They were all released but large ransoms are suspected to have been paid.

- Last month, 53 people, including 23 soldiers, were killed during a military assault on the Abu Sayyaf's main base on Jolo. An army official described it as the biggest battle since 2007, when 15 soldiers and 40 rebels were killed on nearby Basilan island.

(Reporting by Manny Mogato; Editing by Raju Gopalakrishnan and Alex Richardson)