Sydney – A former leader of the Islamic militant group responsible for the deadly Bali bombings has warned that more attacks were likely this year.

Nasir Abbas, who once ran the Philippines branch of Jemaah Islamiah (JI), the Al-Qaeda-linked Southeast Asian terror network, told the Australian Broadcasting Corporation the group aimed to launch an attack every year.

In each of the past four years, JI has been blamed for major attacks between August and October. These are the October 2002 Bali bombings which killed 202 people, the August 2003 Jakarta Marriott Hotel blast, the September 2004 Australian embassy attack and the October 2005 second Bali bombings.

Abbas said Indonesia's most wanted fugitive, Noordin Mohammad Top, had ordered his followers to launch attacks every year. "Noordin had mentioned to his followers that he will do an operation at least once a year. That doesn't mean a big operation," Abbas said. The attacks could come in the form of car bombs or backpack bombs, he said.

Abbas, who was arrested in 2003 and served 10 months in prison for immigration offences in Indonesia, previously had Noordin and the now deceased bombmaker Azahari Husin under his command, ABC said. He is brother-in-law to senior JI member Muklas, who is on death row for his part in the 2002 Bali bombings.

Abbas said JI was weaker than it once was, but that a new instruction manual circulating in Indonesia showed sympathisers how to form independent terrorist cells in a strategy he called "uncontrolled decentralisation". "They can move on their own because they understand that this is their obligation," he said.

Abbas, who was speaking to the ABC's Indonesia correspondent, has cooperated with police and says JI accuses him of being a "traitor".

The Australian government has advised its citizens against travelling to Indonesia since the 2002 attack in Bali that killed 88 Australian holidaymakers.