The optimistic view that the murderous Bali bombing was an aberration has been shattered by a new series of terrorist attacks, particularly against Indonesia. Officials of that country, notably outgoing President Megawati Sukarnoputri and incoming successor Susilo Bambang Yudhoyono have done an admirable job of tracking, arresting and prosecuting the Bali bombers and planners alike. But there is a long way to go yet before Southeast Asia can relax.

The threat by violent extremists was punctuated again last month. A huge bomb blast killed and wounded nearly 200 people in Jakarta, and a second bomb exploded at the Indonesian embassy in France. The unforgivable kidnapping of two innocent Indonesian women by Iraqi terrorists made it clear the threat to peace in our region continues.

The main terrorist group in Southeast Asia is known as Jemaah Islamiyah. JI is both an umbrella front, offering support and manpower to smaller subsidiary groups, and an actual terrorist organisation.

The Bali bombers and the planners of the August 2003 JW Marriott Hotel bomb attack in Jakarta were direct members of JI. The group also has members in Singapore and Malaysia, and according to court testimony has organised cells in Thailand and Cambodia. JI also provides support and leadership to smaller groups, such as KMM in Malaysia. Finally, JI is itself the Southeast Asia subordinate of al-Qaeda, the world's leading terrorist organisation.

JI specifically claimed responsibility for the Sept 9 car bomb explosion outside the Australian Embassy in Jakarta. Although the statement attributed to the group said the attack was against Australia, the casualties and damage belied that. No Australian died; all but one of the nine dead and 180 wounded were Indonesians apart from a five-year-old girl with dual Australian-Indonesian nationality. It was the biggest car bomb ever exploded in Indonesia, and the attack appeared well planned. The aim was clearly to terrorise Indonesians by inflicting heavy, random casualties.

There is little evidence Indonesians are terrorised. Detectives have made several arrests. Forensic scientists identified the suicide bomber and publicised his name, identifying his family. Prosecution continued of the accused head of JI, Abu Bakar Bashir.

In fact, even when terrorists seized the two innocent Indonesian women in Iraq, Jakarta officials quickly refused their demands to release Bashir, and shamed the abductors into releasing the women by their superior moral stand.

Throughout the region, there are manhunts for the top JI fugitives. Malaysian bombmakers Azahari Husin and Noordin Mohammad Top were almost certainly behind the recent blasts in Indonesia. Police chief Da'I Bachtiar said these and other JI members have also tried to bomb several other places and functions, but detectives broke up the attempts. Courts in Thailand, Singapore, Indonesia and Malaysia all are hearing cases against known or accused JI members, and Cambodian prosecutors also are holding accused JI members, including several Thai citizens, pending legal action.

Last month's bombing in Jakarta, more than any recent event, has galvanised the region against the terrorists. Regional cooperation, always promised, has begun to happen.

A Malaysian government statement described the car bombers as ``not only cruel killers but also traitors of Islam and Muslims.'' Philippines President Gloria Arroyo said the region must go after the militants.

More importantly, Muslims not only spoke out, but acted against the extremists who claim to act in the name of Islam. An Arab editorial the day after the bombing noted that the majority of the population of the world's most populous Muslim nation is appalled and outraged by such attacks. More than 1,000 members of the hardline and activist Islamic group Hizbut Tahrir demonstrated against the JI extremists. One of their signs: ``Islam Against Terrorism''.

Such regional and religious solidarity should signal to JI and sympathisers that their violent and murderous cause has no chance of success.

Unfortunately, JI leaders seem unlikely to rejoin the mainstream and battle for their questionable goals through legal means. This is why it is vital to increase regional cooperation against Jemaah Islamiyah and its members.