update Griffith remains the only town unable to access the triple-0 emergency network after two major cables were cut today, shutting down Telstra services in southern New South Wales and the ACT.

Fixed, mobile and broadband networks went down in southern NSW and the ACT today after two fibre optic lines were severed between Wagga Wagga and Griffith, and Bombala and Gundagai.

Residents had to resort to calling local police, fire and ambulance services in case of an emergency, with the network failure taking the triple-0 emergency service out of commission.

Telstra crews were investigating the possibility the cuts may be linked, a spokesman from the telco said.

"It's an unusual circumstance that two (cables) had been cut at the same time affecting the same area," the spokesman said.

Though the cause was yet to be determined, it was possible contractors may have accidentally cut the cable, he said. "Australia is a very big country," he said.

"From time to time contractors or other people using heavy machinery may put a tractor through a cable. I'm not saying that's what happened in this case, but it would appear to be likely."

By 3pm (AEST) triple-0 access had been restored to all major towns in the region except Griffith, with emergency traffic re-routed via Melbourne.

Access also appeared to be restored in the ACT, the Telstra spokesman said.

Emergency crews were working to repair the severed lines, and it was hoped the network could be fully restored by midnight, the spokesman said.

NSW Ambulance Service operations general manager Mike Willis said a contingency plan had immediately been put in place.

"The ambulance service is currently working with Telstra to rectify the problem," Willis said.

He urged people in remote areas still affected by the problem to call their local police, who could contact an ambulance directly.