The police had previously arrested 18 suspects over the December 5th bomb blast in which three people died. Some belonged to a radical Islamic group partly blamed for religious clashes in a neighboring province in which 2,000 people were killed from late 1998 to 2001.

Authorities have evidence linking the Makassar blast to the Bali bombings, as some of the suspects knew militants on trial for the Bali attacks that killed 202 mostly foreign tourists. But asked whether Dahlan, 32, had any link to the Bali blasts in October 2002, Basyir said this was still being investigated. Police claim that the motive of the McDonald's attack was to make a symbolic anti-American strike.

Jema'ah Islamiyah, a regional militant Islamic network, is suspected of staging the Bali blasts and has been tied to Osama bin Laden's al-Qaeda network. Indonesia has been hit by sporadic bomb blasts in recent years, with the latest one ripping through Jakarta's five-star JW Marriott Hotel on August 5th, killing 12 people and wounding 150.