With that in mind, Australia's foreign affairs department has upgraded its official travel advisory, warning that attacks against Western interests were being planned.

The advisory stated: 'There have been recent arrests of high-level terrorist operatives in Indonesia, but we assess terrorists are continuing active planning of attacks.

'These attacks could take place at any time and could be imminent.

'Particular care should be taken at this time to avoid known terrorist targets.'

It also stated that previous attacks in Indonesia showed Bali and Jakarta were priority targets, but warned such 'attacks could occur at any time, anywhere in Indonesia'.

Australia has advised its citizens to reconsider travel to Indonesia since the first Bali bombing in October 2002, in which 88 Australians were among the 202 killed.

The advisory comes after Zarkasih, head of terrorist group Jemaah Islamiah (JI) and Abu Dujana, leader of JI's military wing, were arrested by Indonesian police last month, along with six other suspected militants.

While the arrests were seen as a major blow to JI, an unnamed member told TV channel Al-Jazeera English last month that the lack of leadership could make JI even more dangerous.

He said: 'The situation could become more dangerous now, because some members will be getting impatient without clear instructions from the top.'

AGENCE FRANCE-PRESSE

DANGEROUS LACK OF LEADERSHIP

'The situation could become more dangerous now, because some members will be getting impatient without clear instructions from the top.'
AN UNNAMED JI MEMBER telling TV channel Al-Jazeera English last month