SYDNEY, Australia: Optus said it had suffered another emergency call outage in an area south of Sydney, just 10 days after a broader disruption that the Australian telco said likely contributed to four deaths.

The latest failure has intensified criticism of Optus and its parent company, Singapore Telecommunications (Singtel). The Australian government has called it an "absolutely shocking failure" and demanded answers.

Singtel Group CEO Yuen Kuan Moon will meet Australia's Communications Minister Anika Wells this week, joined by Optus Chairman John Arthur and CEO Stephen Rue, according to the minister's office.

"Singtel takes this matter seriously and will extend full co-operation to the Australian government and authorities to address the Optus issue," the Singapore-based firm said.

Optus said a faulty mobile tower in Dapto, about 100 km (62 miles) south of Sydney, disrupted services, including the "000" emergency number, on the morning of September 28 and affected about 4,500 people.

"Optus continues to investigate the cause ... the issue has been restored," a spokesperson said by email, adding the company had confirmed with police that "all callers who attempted to contact emergency services are OK."

The outage comes less than two weeks after a 13-hour network failure on September 18, caused by a botched firewall upgrade. This disruption disrupted emergency services in two states and the Northern Territory and was linked to four deaths.

That crisis followed a country-wide network blackout in 2023 that triggered a Senate inquiry and led to the resignation of then-CEO Kelly Bayer Rosmarin. Optus is also fighting court action over a 2022 data breach that compromised millions of customer records and was fined A$100 million (US$65.7 million) for "unconscionable" sales practices.

"This can't happen again. This is an absolutely shocking failure from Optus," Treasurer Jim Chalmers told reporters on September 29. He said the government had instructed the Australian Communications and Media Authority, the industry regulator, to carry out a "very thorough investigation."

Rue has acknowledged that human error may have contributed to the September 18 outage, saying internal checks suggested procedures were not followed. Optus is also commissioning an independent review, which is expected to be completed by the end of the year.

Shares in Singtel, listed in Singapore, fell 2.5 percent in afternoon trading.