Powerful 5.5 tremor brings back trauma to quake city

Two people were pulled alive from a collapsed church today after a powerful 5.5 magnitude earthquake hit Christ-church, a city still being rebuilt after the February quake which killed 181.

There was panic in the New Zealand capital as it was rocked at around 1pm local time. It came after a 4.3 tremor half an hour earlier and was followed by a 4.4 quake minutes later.

St John the Baptist church was totally destroyed. People ran from packed shopping centres. "This place is going mad," said fire service spokesman Ian Lynn.

Police said at least seven people were trapped under one fallen building. A bridge reportedly collapsed.

One supermarket worker said items were thrown from the shelves and the floor was littered with food and broken glass. "It was pretty freaky. It felt like it was right under the supermarket," she said.

Reporter Jarrod Booker, who was attending the inquest into 106 deaths at the CTV building during the February 22 quake, said there was severe shaking with the ground "moving side to side". He added: "People started running out of the building, they were quite frightened."

Rocks were seen falling from nearby hills. One Facebook user said they were "not enjoying being up the hill right now ... saw half a bloody cliff fall from that shake." About 47,000 homes in the city's eastern suburbs were left without power after the latest aftershocks. Temperatures were expected to approach freezing. Sediment bubbled up from the earth, a process known as liquefaction.

Christchurch airport, the University of Canterbury, council offices and Riccarton Mall were evacuated.

Mayor Bob Parker said the earthquake felt at least as powerful as the February quake, but much shorter in duration. He had received early reports of buildings buckling in the city centre and was still waiting to hear whether there was injuries to staff working to rebuilf the area. "I must admit I was very concerned. Our building was rattling and shaking. Trees in the streets were waving at crazy angles."

The quake would have brought back traumatic memories for many residents, said Mr Parker. "It doesn't even take a 5.5 magnitude to bring back traumatic memories. Any quake brings it all back. All your can do is wait. That's all. You can't move."

Residents took to Twitter to post about the quake. One said her house "wobbled like crazy", adding: "Big quake. House still moving. Alarms going off everywhere."

Ash from a volcano which erupted in Chile last week has drifted into airspace over Australia and New Zealand disrupting many flights.