Telstra’s 3G and 4G networks went down across Australia on Monday morning, prompting urgent warnings to anyone who might be trying to make a triple-0 call.

It was the third outage the carrier’s customers have endured in May, including a May 4 lightning strike that shut down the national emergency phone network.

Victoria’s Emergency Services Telecommunications Authority said it was aware of the national outage and monitoring any effects on triple zero calls.

“If you’re unable to get through to triple zero from your mobile phone please find a landline phone and try again,” it tweeted. “Continue to call 000 for emergency help.”

NSW Police also warned of potential issues contacting emergency services.

“If you need assistance, use a phone with another carrier or a landline,” it said. “Only call Triple Zero (000) if you have an emergency.”

The weather is @Telstra land is bright and sunny. You can see by the map! pic.twitter.com/pBBF6xYKu0

— @Snoofycat on Threads (@Snoofycat) May 21, 2018

A map on Aussie Outages showed all major cities were affected. At 11.07am (AEST) on Monday, the website had more than 15,000 reports of Telstra network problems – mostly relating to internet, mobile and reception.

Electronic payments through NAB and the CBA were also reportedly affected, as were calls to roadside assistance services.

Telstra also had another outage on May 1, when customers were unable to make or receive calls for several hours.

Monday’s crash brought a fast and furious reaction on social media.

Meanwhile at Telstra. #telstra #outage pic.twitter.com/eMsI6Dkalx

— James 💉💉💉 (@Jwarne) May 21, 2018

https://twitter.com/pizzabo27635309/status/998364362661228546

Telstra took to Twitter to apologise for the outage, but did not confirm the extent of the problem. It referred users to the company’s outage tracker page – but this had its own problems.

Telstra’s official outage tracker … which was also out of action.

“We’re aware of the issue impacting our mobile network. Sorry for any inconvenience,” the company tweeted.

By lunchtime, Telstra said it had bypassed hardware that had been causing an issue and 4G voice and data traffic volume was improving nationally.

“3G voice and data volumes are also improving,” it said. “We’re very sorry for the interruption to services.”

Calls to triple-0 would connect through other carriers’ networks if  necessary, it said.

By mid-afternoon, ESTA said Victoria’s triple-0 service was fully operational and Telstra had advised its mobile and data services were back to normal.