NZ telcos converge on quake-hit Canterbury

New Zealand telcos are scrambling to account for staff and assess their networks in the wake of a powerful 6.3-magnitude earthquake in the Christchurch and Canterbury regions.

This story has been updated by iTnews' New Zealand correspondent Juha Saarinen - including more information on communications interruptions and social media efforts to locate missing persons.

The NZ Ministry of Civil Defence and Emergency Management said the epicenter of the quake was about 10km south-east of Christchurch.

The race was now on to locate survivors but the situation was complicated by multiple aftershocks.

It came only five months after a 7.1-magnitude quake struck Christchurch that caused widespread damage and power cuts that affected some mobile services.

Significant damage reports were filtering through on news services and wires.

"Telecom [NZ] is working intensively to understand which services have been affected by today's earthquake and get these restored as soon as possible," the company said in a brief statement.

"Our thoughts are with the people of Canterbury."

The telco reported that its Christchurch building had suffered "heavy damage but all colleagues accounted for."

Vodafone NZ urged customers not to "overload phone lines with non-emergency calls, stick to TXT and short calls if you can".

Gen-i chief Chris Quin tweeted that clearer information on cellsites was emerging, with "a few affected".

And 2degrees Mobile said: "Hope everyone's ok down there."

The Australian Department of Foreign Affairs and Trade (DFAT) has set up an emergency hotline for those with family and friends in New Zealand: 1300 555 135.

More to come...