Optus network outage affects millions of Australians

Millions of Australians were left without a phone or internet connection on Wednesday after the country's second-largest telecommunications provider experienced an unexplained nationwide outage, Report informs via Reuters.

The outage crippled payment systems and online operations and led to morning peak-hour chaos as train networks and ride share services were down briefly in some cities. Some hospital and emergency services were also impacted.

Optus CEO Kelly Bayer Rosmarin ruled out a cyber attack but in an interview on ABC Radio did not give a reason for the outage, already in its eighth hour.

"It is highly unlikely (that the problem started within software in Optus networks), our systems are actually very stable ... This is a very, very rare occurrence," she said.

"We are working really hard to get it up and running as soon as we possibly can."

Optus is the Australian unit of telecoms firm Singapore Telecommunications and has more than 10 million customers, about 40% of Australia's population.

Some services across fixed and mobile were gradually being restored but it could take a few hours for all services to recover, Optus said later on X, formerly known as Twitter.

The outage comes after a cyber breach last year exposed personal details of millions of Optus customers, including home addresses, driver licence and passport numbers.

The parent company Singtel has said earlier this year that after the cyber attack Optus made several investments to lift its capabilities and provide additional protection for customers.

Singtel shares were down 3.2% on the Singapore bourse after reports of the major outage.

Melbourne's train networks were forced to shut down for about 30 minutes due to the outage, resulting in delays during the morning rush, media reported.

Hospitals and emergency services across the country were also hit by the outage. Ramsay Health Care, which owns 70 hospitals and clinics in Australia, said its phone services were impacted. Emergency triple zero ("000") calls were not working from Optus landlines.

Banking services, including some ATMs using Optus, were also impacted. Commonwealth Bank, the country's biggest lender, said some customers may encounter difficulties with its services.