Optus has been hit by a nationwide outage, with its mobile phone and internet services down for millions of Australian customers and businesses.
On its website early on Wednesday, Optus said its engineers were investigating a network fault impacting customers.
Mobile phone users are unable to make or receive calls and mobile internet services are down.
An Optus spokesman said the company was working to restore services as a priority.
“We are currently working to identify the cause and apologise for any inconvenience,” the statement to AAP read.
“In case of an emergency, customers can still call 000.”
Federal Communications Minister Michelle Rowlands said she had spoken to Optus about the “significant” network problem but she couldn’t say if it stemmed from a cyber attack.
“I would be reluctant to speculate on that at this stage,” she told ABC Radio Sydney on Wednesday.
“The CEO has been in contact with me and did not indicate that that was the case, so I would be reluctant to say anything else on that matter.”
Melbourne train services were also interrupted early on Wednesday, reportedly due to the Optus outage.
All metropolitan services were stopped from about 4.30am due to a communications fault across the train network.
Metro Train services started to resume just before 6am but major delays continued throughout the morning peak as services were restored.
“We apologise to our passengers for the delay to their travel this morning,” Metro Trains chief executive Raymond O’Flaherty told AAP in a statement.
“We thank passengers for their patience while trains return to their normal timetable.”
Service NSW call centres and phone lines across Northern Health’s hospitals and virtual emergency department in Melbourne’s north were also down due to the Optus outage.
Source: AAP
