What is Jemaah Islamiah?
A five-minute primer on an issue making headlines
The release from jail last week of Muslim leader Abu Bakar Bashir has renewed fears about the dangers posed by the terrorist group he is accused of leading.
Was Bashir involved in creating Jemaah Islamiah?
The organisation commonly known as JI is believed to have been formed in Malaysia in the late 1980s by a group of exiled Indonesian extremists. Around two decades earlier Mr Bashir and Abdullah Sungkar resuscitated the Darul Islam sect, a radical movement whose goal was to create a single Islamic state under sharia law across Southeast Asia - from Thailand in the north to the far south-eastern tip of the Indonesian archipelago. Before fleeing to Malaysia in 1982 both men spent several years in jail as the Suharto regime cracked down on anti-government groups. They returned in 1998, when Suharto was deposed.
When did JI turn violent?
After several key members returned from Afghanistan, where they fought for the mujahedeen against Soviet occupation. There, many of the personal connections that define today's global network of Islamic terrorist groups were formed, including links between al-Qaeda and JI. Key to JI's change in strategy was mujahedeen Riduan Isamuddin - better known as Hambali - who met Mr Bashir in the early 1990s. Hambali became JI's military leader, and is said to have orchestrated the group's metamorphosis into small and autonomous terrorist cells scattered across Southeast Asia.
How many attacks have been linked to JI?
It's a long list, including none more devastating than the huge Bali car bomb that killed 202 people - most of them tourists, including 11 Hong Kong residents - in October 2002. In Indonesia, JI has also been blamed for a string of deadly bombs: in Bali again last year, at the Australian embassy in Jakarta in 2004 and the city's JW Marriot Hotel in 2003. Christian churches have also been attacked. In 2000, the Philippines ambassador was seriously injured in an assassination attempt that left two dead. The following year Singaporean officials foiled JI plans for multiple suicide blasts against western targets.
How much success have the authorities had in disrupting their operations?
Under pressure from western governments, Indonesian authorities have taken strong action against JI. Analysts believe the group's capabilities have been drastically reduced by the arrests of hundreds of members and the freezing of financial assets. Hambali's capture in 2003 in Thailand was hailed as a major breakthrough. Similar optimism greeted the recent killing of chief bomb maker, Azahari bin Husin, in a shoot-out with Indonesian police. But key figures are still on the run and experts fear Mr Bashir's release from jail could help rejuvenate the group. The 67-year-old - who called the Bali bombers 'holy warriors' after his release last week - denies being JI's spiritual leader. He claims the group does not even exist.