Jemaah Islamiya (JI) is an Indonesia-based Islamic extremist group with cells operating throughout Southeast Asia. The group’s stated goal is to create an Islamic state—or caliphate—that would encompass Malaysia, Singapore, Indonesia, Brunei, the southern Philippines, and southern Thailand. JI has been responsible for several major, lethal bombings against Western targets in Indonesia, including the attack on a nightclub in Bali, Indonesia, in 2002 in which 202 people were killed; the car bombing of the Jakarta JW Marriott hotel in 2003; the truck bombing of the Australian Embassy in 2004; the October 2005 bombings of tourist sites in Bali that killed 23 and injured over 100; and the July 2009 bombings at the Marriott and Ritz-Carlton hotels in Jakarta that killed nine, including two suicide bombers, and injured over 50.

Since 2001, JI has suffered significant blows from counterterrorism operations that resulted in the deaths or capture of hundreds of operatives. Although JI spiritual leader Abu Bakar Bashir was released from prison in June 2006, authorities detained operations chief Hambali in August 2003, killed chief bombmaker Azahari Bin Husin in November 2005, and, in June 2007, arrested acting JI leader Zarkasih and the group’s military commander, Abu Dujanah. In 2008, JI operatives Agus Purwantoro and Abu Husna were captured in Malaysia and transferred to Indonesian police custody, and, in April 2008, an Indonesian court sentenced two senior JI leaders, Abu Dujana and Zarkasih, to 15 years in prison and labeled JI a terrorist group. In July 2008, Indonesian police seized explosives and arrested 10 members, including one Singaporean, of a JI cell in south Sumatra, disrupting operational plans to attack specific Christian and Western targets.

In February 2008, Singaporean JI leader Mas Selamat Kastari escaped from a Singaporean prison. He was recaptured in Johor, Malaysia, in April 2009. Police continue to hunt other senior JI leaders and operatives who are at large in Indonesia and elsewhere in Southeast Asia. In August 2009, Indonesian police raided safehouses in Bekasi and Central Java, killing multiple suspects in the Jakarta hotel bombings and recovering explosives. In September, Noordin Mohammad Top, who reportedly masterminded the 17 July 2009 explosions at the two hotels in Jakarta, was killed in a raid by Indonesian security forces.