150 claims after swarm of quakes

Backpackers gather outside after the 4.9 quake. Photo / Simon Baker

The Earthquake Commission (EQC) has received 150 new claims following the latest swarm of aftershocks to hit Christchurch and is treating them as a separate earthquake.

EQC chief executive Ian Simpson said today the current spate of aftershocks would not be treated as part of September 4`s 7.1 magnitude quake.

"That means that people whose property was damaged by the quakes will have three months to lodge their claim and there is no need to rush home to check if they are away," Mr Simpson said.

Most of central Christchurch has been reopened to business after yesterday's aftershocks caused part of the CBD to cordoned off.

The biggest tremor measuring magnitude 4.9 shook the city at 10.30am yesterday causing shoppers to flee as bricks and mortar crashed from buildings. Around two dozen aftershocks were felt within the space of 36 hours.

Acting mayor Ngaire Button said most of the cordons in central Christchurch had been removed following a briefing this morning.

She told Radio New Zealand that Cashel Mall from Colombo street to Oxford Terrace would remain closed today after two aftershocks early today caused further damage to buildings.

Police, council staff and engineers would be carrying out assessments through out the day.

Yesterday's aftershocks were a setback for retailers for which Boxing Day sales were so important, Ms Button said.

"It's very difficult for central city because we've all been working together to try and bring about this recovery, Boxing Day sales are so important for our retailers."

There were no reports of injuries, despite the largest aftershock happening mid-morning on one of the busiest shopping days of the year.

Water, wastewater and stormwater networks were undamaged, but power was knocked out to about 40,000 properties.

Electricity was restored by about midday.

The aftershocks were not unexpected and could still happen in the next few months, GNS Science seismologist John Ristau said.

"This is a bit of a wake up call, to kind of say that you can still get large magnitude aftershocks," he said.

- NZPA