The initial quake measured 5.8 magnitude, and prompted the evacuation of public buildings and the airport

This article is more than 8 years old

This article is more than 8 years old

A series of strong earthquakes have struck the New Zealand city of Christchurch, 10 months after an earlier quake devastated the city centre.

The US Geological Survey said the initial quake on Friday measured 5.8 magnitude but there was no tsunami alert issued and no immediate reports of widespread damage in the city.

One person was injured at a city mall and was taken to a hospital, and four people had to be rescued after being trapped by a rock fall, Christchurch police said in a statement.

Local reports suggested the quake rattled buildings, sending goods tumbling from shelves and prompted holiday shoppers to flee into the streets.

The first quake struck in the afternoon, 16 miles (26km) north of Christchurch and 2.5 miles (4km) deep, the US Geological Survey said. Minutes later, a 5.3-magnitude aftershock hit, and about an hour afterwards the city was shaken by another 5.8-magnitude tremor. Both aftershocks were less than 3 miles (5 km) deep.

The city's airport was evacuated and all shopping centres shut down as a precaution.

Warwick Isaacs, demolitions manager for the Canterbury Earthquake Recovery Authority, said most buildings had been evacuated "as an emergency measure".

Photograph: Guardian

Christchurch is still recovering from the earthquake in February that killed 182 people and destroyed much of the downtown area.

The area has recorded more than 7,000 earthquakes since a magnitude-7 quake rocked the city on 4 September 2010. That quake did not cause any deaths.

Rock falls had occurred in one area and there was liquefaction when an earthquake forces underground water up through loose soil in several places, Isaacs told New Zealand's National Radio.

"There has been quite a lot of stuff falling out of cupboards, off shelves in shops and that sort of thing, again," he said.

Isaacs said his immediate concern was for demolition workers involved in tearing down buildings wrecked in previous quakes.

"It ... started slow then really got going. It was a big swaying one but not as jolting or as violent as in February," Christchurch resident Rita Langley said.

"Everyone seems fairly chilled, though the traffic buildup sounds like a beehive that has just been kicked as everyone leaves town."

The shaking was severe in the nearby port town of Lyttelton, the epicentre of the 22 February quake.

"We stayed inside until the shaking stopped. Then most people went out into the street outside," resident Andrew Turner said. "People are emotionally shocked by what happened this afternoon."

About 15,000 homes were reported without power after electricity lines were felled in the city's eastern suburbs. Sewerage services were also cut. Hundreds of miles of sewer and fresh water lines have been repaired in the city since the February quake.

One partly demolished building and a vacant house collapsed after Friday's quakes, police said.

Central City Business Association manager Paul Lonsdale said the quakes came at the worst possible time for retailers, with people rushing to finish their Christmas shopping.

Despite the sizable quakes, there was no visible damage in the central business district, where 28 stores have reopened in shipping containers after their buildings were wrecked by the February quake, he said.