SYDNEY, Australia (AP) -- Australia's Prime Minister John Howard on Monday defended warnings from his government that a terrorist attack in Indonesia may be imminent, despite there being no direct intelligence that the chances of a strike had increased.

The Foreign Affairs Department reissued a travel advisory to Indonesia on Sunday, warning Australians to rethink travel to the Southeast Asian country because of the threat of terrorist attacks. The advisory did not raise the threat level for attacks.

Foreign Minister Alexander Downer said Sunday the advisory was reissued because of the June 9 arrest in Indonesia of Abu Dujana, an alleged leader of terrorist group Jemaah Islamiyah, and that a terrorist attack "could be imminent."

Jemaah Islamiyah is blamed for several attacks against Western targets in Indonesia over the last few years, including two bombings on the resort island of Bali in 2002 and 2005.

Nearly 100 Australians were killed in the two Bali attacks.

On Monday, Downer said the travel warning would have been upgraded if there was any information about a specific attack.

"We don't have any information designating a specific target or for that matter a specific time of a terrorist attack," Downer told Australian Broadcasting Corp. radio.

Howard said the advisory was based on "strong intelligence" and that such a warning was not taken lightly because it could affect relations between Australia and Indonesia.

"We are the last country in the world to want to say anything unnecessarily serious about Indonesia because Indonesia is a friendly country," Howard said on Nine Network television.

"But we have, above all of that, a great obligation to warn our citizens if we think there is the possibility of something happening."