Australian government agencies held crisis talks on Sunday in response to a cyber incident that has disrupted operations at key ports across the country.

Port operator DP World halted internet connectivity at ports in Sydney, Melbourne, Brisbane and Fremantle on Friday to prevent "any ongoing unauthorised access" to its network, a spokesperson said.

The ongoing disruption has not prevented containers from being taken off vessels, but trucks needed to transport them have not been able to drive in or out of the terminals, DP World senior director Blake Tierney said in a statement.

"The company is working around the clock to restore normal operations safely," he added.

Australian Federal Police have said they are investigating the incident.

The "interruption is likely to continue for a number of days and will impact the movement of goods into and out of the country", National Cyber Security Coordinator Darren Goldie said on X, formerly Twitter.

"DP World Australia has advised it has restricted access to its Australian port operations while it investigates the incident," he added.

After holding emergency meetings on Saturday, Goldie again convened the National Coordination Mechanism on Sunday with representatives from government, maritime and logistics sectors to manage the government's response.

Australia's National Emergency Management Agency also attended the talks.

Lucrative target

Goldie, an air marshal in the Royal Australian Air Force, was appointed the inaugural national coordinator last July in response to several cyber attacks.

Cybersecurity experts have said inadequate safeguards and the stockpiling of sensitive customer information have made Australia a lucrative target for hackers.

Medibank, Australia's largest private health insurer, said in November 2022 that hackers had accessed the data of 9.7 million current and former customers, including medical records related to drug abuse and pregnancy terminations.

Just two months earlier, telecom company Optus fell prey to a data breach of similar scale in which the personal details of up to 9.8 million people were accessed.

Those two incidents were among the largest data breaches in Australian history.

Optus, Australia's second-largest phone provider, apologised to its more than 10 million customers last week over a "technical network outage" that crashed electronic payments, disrupted phone lines used by emergency services and stopped people accessing government services.

The Australian government has launched an investigation into that unexplained glitch, although it has not been described as a cyber attack.

There were 76,000 cybercrimes reported to the Australian Cyber Security Centre last year, although experts warn many more go unreported.