Australia's consulate in the Indonesian city of Surabaya has boosted security measures after a social media post urged militants to "kill" one of its diplomats there.

Key points: Consulate staff cancel plans to attend an event at a university

Consulate staff cancel plans to attend an event at a university Threat was posted to Telegram app

Threat was posted to Telegram app A series of bombings killed about 30 people in Surabaya in May

The scare comes just weeks after Australia opened the consulate in Indonesia's second-biggest city.

In May, the Islamic State group claimed responsibility after Indonesia suffered its worst militant violence in more than a decade, when a series of suicide bombings in Surabaya killed about 30 people, including the attackers.

On Thursday, the Department of Foreign Affairs updated its travel advisory, noting consulate staff in Surabaya would not be attending an event at the city's Airlangga University "due to heightened security concerns".

Two security sources in Indonesia, speaking on condition of anonymity, said the threat stemmed from a social media post that urged Indonesians in Surabaya and East Java province to "kill this Australian official".

The message was linked to a photo advertising a function at the university for Australian alumni that was due to be attended by consular officials.

"Australia is a member of the international coalition against Islamic State which massacred thousands of Muslims. Revenge the blood of Muslims," said the message, which was verified by officials as the source of concern.

One security source in Indonesia said the posting on the Telegram app, which later spread to other social media platforms, appeared to have originated in the Netherlands.

The source said there was no evidence of "anyone local responding to this message".

Foreign Minister Julie Bishop was in Surabaya earlier this month. ( Antara Foto: Zabur Karuru via Reuters )

Since the suicide attacks in the city three months ago, police have detained nearly 250 suspected militants and killed 21 others in a nationwide crackdown.

Indonesia has grappled with violent Islamist militancy for almost two decades, and in 2004 a bomb attack on the Australian embassy in Jakarta killed 10 Indonesians and wounded more than 100.

To safeguard the Asian Games, currently underway in the capital Jakarta and the city of Palembang on Sumatra island, authorities have deployed 100,000 military and police.

Neither the threat on social media, nor the Australian advisory, said the Asian Games was a target.

Even so, the advisory says the Australian Government continues to "receive information indicating terrorists may be planning attacks in Indonesia".

The overall level of Australia's advice was not changed. It warns travellers to "exercise a high degree of caution" in Indonesia.

Reuters