Spokeswoman Nicky Preston said a road-working contractor accidentally cut one of its major fibre-optic cables near Matamata in the Waikato just before 9am.

By coincidence, the same cable was separately cut in Napier earlier on Thursday morning by another "third party".

Vodafone infrastructure director Tony Baird said at 1.30pm that repairs were still continuing, but services had been now restored.  

“While we have a number of resilience measures in place to ensure customers stay connected wherever possible, because there were two separate fibre cuts combined on the same fibre chain, it meant a reduced ability to reroute traffic in the area," Baird said in a statement.

“With alert level 3 construction work back underway, and with shovel-ready projects likely to get started, we urge contractors to check before they dig at all times," he added.

Mobile and internet broadband services relied on underground fibre cabling to function, he said.

"While we appreciate that contractors are working to increased time pressures, accidental damage to underground cables can cause massive disruptions, which was evident today."