The three young suicide bombers who killed 19 other people in Bali represent a new generation of violent militants in Indonesia, Bali police chief Made Mangku Pastika said on Friday.

Police say explosives on the bodies of the three ripped through restaurants on the tourist island last Saturday, killing 22, including the three men, and wounding 146.

Police believe the bombers had help and have launched a huge manhunt for others involved, aided by some foreign law enforcement officers and the Indonesian military.

Attention has centred on Jemaah Islamiah, the al-Qaida-linked Islamic militant network blamed for past attacks in Indonesia, and two of its leaders, Malaysians Azahari bin Husin and Noordin M. Top.

But experts say much of the old Jemaah Islamiah structure has been destroyed, and the two Malaysians may have formed fresh organizations and recruited new personnel.

Asked about that and reports that the bombers might have been only recently trained, Pastika told reporters:

"They come from a new group. A new generation means that (they) are not known by the old group."

Late on Thursday a Western diplomat in Jakarta also suggested the bombers did not necessarily come from Jemaah Islamiah, saying: "there (are) also of course a lot of other people out there trained in the camps."

But the diplomat, who declined to be identified, said the fact that relatively small bombs had been used in the Bali attacks rather than the car bombs favoured in past Indonesian blasts did not necessarily mean the Bali conspirators had different roots.

"Our concern has always been that once you really got enough pressure on these guys to make it harder for them to assemble the car bombs and do the big splashes like they like to do, that they would then go to the tried and proven method of backpacks and things like that," he told reporters.

Authorities blamed all those attacks on Jemaah Islamiah, and believed Azahari and Top had helped mastermind them.

Source: China Daily