Who are the Abu Sayyaf?

The militant Islamic group Abu Sayyaf is one of several guerrilla organisations involved in a resurgence of violence in the Philippines during the past year.

Previously a faction within the Moro National Liberation Front (MNLF), it split off in 1991 to pursue a more fundamentalist battle against the Philippine authorities.

It pulled off a major coup in 2000 when it kidnapped a group of foreign tourists from a Malaysian resort island.

The group operates in the south of the country, where other militants have been warring for almost 30 years for an Islamic state, independent of the mainly Christian Philippines.

Abu Sayyaf - or "father of the swordsman" in Arabic - was named after a mujahedin fighter in Afghanistan in the 1980s, where a number of its members fought against the Soviet-backed regime.

Religious war

Hostage-taking is the latest in a series of actions which began in the early 1990s with a spate of bombings, assassinations and kidnappings of priests and businessmen.

Abu Sayyaf rebels give a jungle press conference

In December 1994, the group bombed a Philippines Airlines plane on a flight from Manila to Tokyo, killing one passenger.

But most of its activities have centred on southern Mindanao.

An attack on the town of Ipil in 1995 left 50 people dead, and a grenade attack on a department store in Zamboanga in 1998 injured 60.

Analysts say such attacks show the group - which is believed to have a core membership of around 200 - is trying to spark a religious war.

The Philippines Government says Abu Sayyaf has been trying to evict Christians from its Basilan Island base.

Muslims protest in Manila - but some Moros have taken a more violent path

As well as suspecting links with the mastermind behind the US World Trade Centre bombing, Ramzi Youssef, Manila believes it is connected to the man who tops America's most-wanted list, Osama bin Laden.

Analysts say that Abu Sayyaf has received arms and munitions from Afghanistan.

Leaders

Commander Robot: In charge of the hostage-takers

The founder of Abu Sayyaf - Abdurajak Abubakar Janjalani - was an Islamic scholar.

He was killed in a clash with the Philippine Army in December 1998.

The group responsible for the latest hostage-taking appears to be led by Galib Andang, also known as Commander Robot.

He has been allegedly involved in earlier kidnappings.

Moderates

The Moros, who converted to Islam in the 14th century, have long resisted the Philippines' Catholic rulers, dating back to the Spanish colonial period.

Philippine Army patrols try to keep the rebels in check

Abu Sayyaf is the most militant of the anti-Manila groups and wants an independent Islamic state in Mindanao - an impoverished region with an annual income a mere fifth of the national Philippines average.

Moderates are calling simply for the implementation of a planned 13-province autonomous region in the southern Philippines.

Another group, the MNLF - from which Abu Sayyaf split - announced a ceasefire in 1996, and has been pursuing talks with government officials.

A third group - the Moro Islamic Liberation Front, which numbers around 15,000 fighters - had also started a ceasefire, but then halted all dialogue with the government after military assaults on its camps in July 2000.