Australia issued a warning on Thursday about possible militant attacks being planned in Indonesia, only days after a similar warning for the Malaysian capital, another sign of rising concern over militancy in Southeast Asia.

"Recent indications suggest that terrorists may be in the advanced stages of preparing attacks in Indonesia," said the travel advisory on an Australian government website

The Australian Department of Foreign Affairs and Trade did not respond to a request for more details.

Australia issued a similar statement on Sunday about possible attacks in and around Kuala Lumpur.

The British, New Zealand, Canadian and other diplomatic missions in Malaysia soon followed with notices advising against travel to coastal islands in the eastern state of Sabah.

Malaysia has been on high alert since a bomb and gun attack in Indonesia's capital in January in which eight people were killed, including four attackers. The attack was claimed by the Islamic State militant group.

Australia has consistently placed Indonesia in the second-lowest of four warning categories, recommending that travellers "exercise a high degree of caution".

Indonesia has been cracking down on suspected militants since the attack in Jakarta last month.

However, a spokesman for the Indonesian national police, contacted after the Australian warning was issued, said there were no indications of an imminent attack.

"We're working continuously with relevant institutions and with the public to maintain security," said Agus Rianto. – Reuters