"The security authorities are presently working their utmost to investigate the bombings and to arrest the perpetrators and bring them to justice," the embassy said in a statement.
But embassy officials refused to say if the Indonesia-based Jemaah Islamiyah, an affiliate of Osama bin Laden’s al-Qaeda terrorist network, was responsible.
"There’s a possibility but we have yet to complete the investigation," press officer Andang Tramana said in an interview.
Former ambassador to Indonesia Leonides Caday said the Bali massacre should prompt Jakarta to finally act against terrorism with more speed.
"There will be pressure from Australians, Americans, Germans and other nations for Indonesia to do something," Caday, now a senior foreign affairs adviser, said in an interview.
Indonesia is under increasing international pressure to arrest an Islamic cleric, Abu Bakar Ba’asyir, earlier tagged as Jemaah Islamiyah’s leader by an alleged ranking al-Qaeda leader detained by the United States.
Ba’asyir lives openly in Indonesia and is a self-confessed admirer of Bin Laden. He, however, denies he is a terrorist. Jakarta refuses to arrest him, citing lack of evidence.
Jemaah Islamiyah reportedly operates in at least five countries – Indonesia, the Philippines, Malaysia, Singapore and Brunei. Philippine security forces are hunting down the group, believed to be recruiting local members.
Police suspect the group is involved in the bomb attack on Oct. 2 in Zamboanga City that killed a US Green Beret and three Filipino civilians.
Early this year, Philippine courts sent to prison two alleged members of the group, Fathur Rohman al-Ghozi and Agus Dwikarna, for illegal possession of explosives.
Philippine intelligence officials said al-Ghozi and Dwikarna were involved in the 2000 Rizal Day bombings in which scores of people were killed in a string of bomb attacks across Metro Manila. Al-Ghozi and Dwikarna denied the charge.
US and regional intelligence officials interviewed by US news organizations said Jemaah Islamiyah was also responsible for the bomb attack on Caday in August 2000.
Caday – who now walks with the help of a cane – was seriously wounded in car bomb attack just outside his residence in Jakarta. Three people, including an Indonesia security guard, were killed.
The attack was reportedly in reprisal for a massive Philippine military offensive against the secessionist Moro Islamic Liberation Front – which reportedly has ties with al-Qaeda – that year. The MILF denied the accusation.
Last month, US news reports said al-Qaeda has been moving its operations to Southeast Asia after the loss of its bases in Afghanistan and plans to attack US interests in Indonesia, Malaysia, the Philippines, Singapore, Thailand, Taiwan, Vietnam and Cambodia.
It reportedly has formed ties with at least nine local militant groups – including Jemaah Islamiyah – in Indonesia, Malaysia, Myanmar, the Philippines, Singapore, Thailand.