After killing one of Southeast Asia's most wanted terrorists last week, Indonesian security officials face a daunting task in catching remaining militants who have grown more independent or moved to the Philippines to regroup, recruit, and share skills.
Azahari Husin, who was killed Wednesday in a gunbattle, had been accused of involvement in most major bomb attacks in Indonesia in recent years, including the 2002 Bali blast that left 202 people dead. Indonesia's president said police found bombs and plans for more attacks in the home where they cornered Azahari.
But the same day, another senior member of the Jemaah Islamiah (JI) terrorist network, Noordin Mohammad Top, escaped authorities elsewhere on Java. And Philippine security officials, meanwhile, say they detect the hand of two other top Indonesian militants in recent terrorist strikes on Manila and the conflict-torn island of Mindanao.
Moving against the remaining JI leaders will test Indonesia's new antiterror capabilities, including a revived village-level network of informants and newly set up military antiterror units, as well as the ability of regional governments to cooperate as militants find safe havens in spots like Mindanao.
"For an actual terror network that has been actively conducting attacks, [Azahari's death] clearly will have a great impact," says Ansyaad Mbai, Indonesia's antiterror chief. "But we all know that terrorism is a crime based on ideology and politics, and will not stop just because of the death of a certain figure."
Mr. Mbai says intelligence shows that extremists are recruiting and working in small independent groups, each capable of launching attacks. "Each is not tied to a hierarchy," he says. Azahari, for instance, was a leading bombmaker for the group but he is not believed to have held a formal role in JI.
Azahari was located after police followed a series of leads arising from the terrorist attack on Bali last month.
In an effort to harness more such leads, the Indonesian military in the last month has restarted a village-level network of noncommissioned officers and civilian spies that had gone dormant with the fall of dictator Suharto in 1998. The military has also set up a dozen special antiterror desks to coordinate efforts with the police.
After last month's Bali bomb attack, Indonesia's President Susilo Bambang Yudhoyono ordered the military to "get more involved on the war on terror."
The Indonesian government is also reportedly considering the formation of a regional counter-terrorism task force, something that may be proposed at a meeting of regional police chiefs this week.
Greater regional cooperation is of growing importance as security officials in the Philippines notice the handiwork of two Indonesians in recent attacks there. The two men, Dulmatin and Umar Patek, are among the most wanted in Southeast Asia. The US government has offered a $10 million reward for the capture of Dulmatin, who uses the alias Joko Pitono, and $1 million for Patek.
Dulmatin is an Afghan-trained expert in explosives whom Philippine officials say primed a concealed bomb that ripped through a passenger ferry off the coast of Manila in February 2004. Over 100 people died in the attack, which was claimed by Abu Sayyaf, a ruthless militant group that was seeded in the early 1990s by Al-Qaeda.
Philippine officials initially ridiculed the idea that Abu Sayyaf, a group that had become notorious for kidnappings and banditry, had plotted the attack. But forensic tests and confessions from detained suspects confirmed its involvement and pointed to the threat of an alliance between Abu Sayyaf and Indonesian fugitives seeking to ignite a regional firestorm.
"This is the dangerous nexus. You take an indigenous movement and graft it onto an international movement with technology transfer," says a Western diplomat. "Abu Sayyaf has moved from piracy to being part of the jihadist movement."
Mindanao has long provided sanctuary for Indonesian and other foreign extremists who used personal ties to Islamic rebels to run terrorist training camps. Jemaah Islamiyah used these camps to train Indonesians and other Southeast Asians in battlefield skills, handling explosives, and building bombs.
A crackdown by the Philippine Army has disrupted the larger camps and forced the JI operatives underground, say officials. But intelligence reports indicate that mobile trainings have continued and are capable of producing new crops of operatives who imbibe JI's fanatical worldview and ruthless terrorist tactics.
Complicating the task for investigators is the shifting identities of terror suspects, with considerable overlap between JI, Abu Sayyaf, and other extremists. Even Dulmatin, who reportedly helped Azahari build the truck bomb used in Bali in 2002, may be relying on his own network outside of the JI structure, say officials.
This would mirror events in Indonesia, where Azahari and Noordin Top are believed to have led a breakaway faction dedicated to anti-Western violence, rather than JI's original goal of fighting for an Islamic caliphate in Southeast Asia.
But such internal fissures are unlikely to end immediately the terrorist threat and may instead spawn splinter cells that feed off Muslim extremism in pockets across multiethnic Southeast Asia. That makes Mindanao a crucial part of the equation.
"If we hit them here, they adjust. If they're hit in Indonesia, they adjust," says Rodolfo Mendoza, a Philippine police official.