Indonesian police yesterday refrained from apportioning blame for the latest bombings on Bali, insisting that the investigation was at too early a stage to draw any conclusions.
Most terrorism experts have been less circumspect, with almost all agreeing that two Malaysians, Azahari Husin, who has a doctorate from Reading University in England, and Noordin Top, were the masterminds.
Despite no one claiming responsibility for the attacks, there is strong evidence to suggest these senior bomb makers of Jemaah Islamiyah, the southeast Asian terrorist network with links to al-Qaeda that wants to create a regional Islamist caliphate, did oversee the operation.
"Azahari and Noordin Top have got to head the list of suspects," said Sidney Jones, an expert on militant Islam in the region. "They're among the few people who've got the determination and the capacity to pull something like this off."
The first clue is the modus operandi, that was a virtual replica of the October 2002 Bali bombings, which was Jemaah Islamiyah's most deadly attack to date, killing 202 people. Both attacks used suicide bombers and comprised three bombs; two close to each other both geographically and in time, and a third at a similar time but different location. Then there are the targets: easy-to-hit premises with little security where young men would go unnoticed.
Finally, there is the noticeable lack of a claim of responsibility, a feature of the previous Bali bombings, Jemaah Islamiyah's attack on the Marriott hotel in Jakarta in 2003 and on the capital's Australian embassy last year, which the duo also masterminded.
Dr Azahari is dubbed the "Demolition Man" in his homeland for his bomb-making ability. He studied in Australia for four years in the 1970s and 10 years later studied maths and engineering at Reading, where he was reportedly so impressive a student that he was asked to stay on for a PhD, which he did in 1990.
His transformation into an Islamist militant came several years later when he fell under the spell of the founders of Jemaah Islamiyah, including its spiritual leader, Abu Bakar Ba'asyir.
A few years later he trained in Afghanistan and the Philippines, where he concentrated on honing his skills with explosives.
Jemaah Islamiyah has suffered setbacks, with a string of arrests in the past few years, but experts say there is a deep well of young radicals willing to become suicide bombers.
"We aren't looking at initials or names of organisations any more," one Indonesian government counter-terrorism official said. "We're looking at the individuals and where they've come from." - (Guardian service)