The federal government is warning the arrest of alleged Bali bomber Umar Patek could spark a violent response from extremists in Indonesia.
It is believed Patek, suspected of playing a key role in the 2002 nightclub bombings that killed 202 people, including 88 Australians, was arrested in Pakistan earlier this year.
Foreign Minister Kevin Rudd has hailed the arrest as a major win in the fight against terrorism.
But Mr Rudd's Department of Foreign Affairs and Trade is warning the arrest could spark a violent backlash.
"The reported arrest in Pakistan of Umar Patek ... may increase the risk of violent responses in Indonesia in the short term," DFAT says in its latest travel warning.
"On some occasions where high profile extremists have been detained or killed, there has been a strong response from some supporters in Indonesia, including acts of violence."
Recent information indicates terrorists may be planning attacks in Indonesia which could take place at any time, DFAT says.
Any terrorist attack is most likely to focus on places where large numbers of Westerners gather, it warns.
DFAT's overall level of advice for Indonesia remains "reconsider your need to travel".
Patek is suspected of having served as Jemaah Islamiah's deputy field commander for the Bali bombings.
The 40-year-old was the final senior planner of the 2002 attack still at large.
He is wanted in several countries, including Australia, Indonesia, the Philippines and the United States.
He is believed to have trained in Afghanistan and Pakistan during the 1980s and 1990s and has been linked to al-Qaeda.