A central Christchurch building was being demolished after it was damaged further by a 5.3 magnitude aftershock yesterday, but early indications suggest the city has escaped significant new damage, authorities say.
The quake shook the battered city at 5.49pm yesterday and was followed overnight by a number smaller aftershocks, the largest of which measured 4.1 on the Richter scale.
The aftershock was among the largest to hit the battered city since February 22's deadly 6.3 tremor.
Civil Defence authorities said the Strategy Building in Victoria Street had become too dangerous to remain standing and was being demolished. Nearby roads were closed.
Some houses in the Lyttelton, Redcliffe, Mt Pleasant and Estuary Road areas were without water as repairs take place on 12 bursts water pipes.
Work was underway to restore water to those properties.
Engineers were in the central city this morning to assess any further damage caused by the 5.3 aftershock.
And until this assessment was completed there would be no access for business owners to the red zone.
The 5.3 magnitude quake was centred within 5km of Lyttelton, 12km southeast of central Christchurch, at a depth of 11km, GNS reported.
Dramatic footage from a wedding on the top floor of the George Hotel, which had only just reopened after the February 22 earthquake, shows how violent the shaking was.
MAYOR SAYS SHAKE 'VERY SEVERE'
Christchurch mayor Bob Parker told the Sunday Star-Times the quake was "very severe" and felt like a bus being driven over a cattle stop. He was at a community meeting in Bromley when the quake struck and said many people were very shocked and had to be escorted home.
Parker said he had heard no reports of injuries or that buildings had collapsed after the jolt but there were reports on Twitter of some liquefaction and rocks tumbled down the cliffs in Sumner.
Parker said scientists had been predicting a quake "around a 5 magnitude" for some time and this "was at the upper end of that".
He immediately drove with his wife Jo to his parents' home in the Heathcote Valley, one of the areas badly hit in the February 22, 6.3 magnitude quake.
On the way there he saw a lot of people who had evacuated their homes and were standing on footpaths and streets with neighbours.
"Power is out over a large area of the city and I've seen some minor damage but mostly further collapse to buildings behind barricades where a wall might have fallen or some more blocks come off," he said.
He said his parents were also shocked but keen to inspect further damage to their home.
He was about to head to the Civil Defence Headquarters in the city for further updates but said he did not expect any significant further damage.
"In my experience, this level of damage would be fairly typical," he said.
Sumner resident Terry Hill said it was a solid, short shock, which was powerful enough to break the neighbour's water cylinder.
"It rocked badly. I opened all the doors, but it certainly wasn't as bad as the February earthquake."
Wife Lorraine said Sumner's supermarket looked like a war zone with smashed wine bottles strewn across the floor. But power was still on and the shop remained open.
She confirmed that rocks had fallen from the cliff onto the Sumner roads, but no one appeared injured.
About 20,000 homes and businesses were without power.
Orion chief executive Roger Sutton said due to violent shaking, power sub-stations automatically shut down. "When they think they're in danger they shut down to minimise damage."
Orion hoped to have power restored during the evening.
TelstraClear said 34 of its roadside cabinets were down causing loss of service for phone customers.
Dixie McGregor, who works at the Pegasus Arms on Oxford Tce said emergency services have been mobilised.
"We've got a pub full of people but it's OK here, but all I can see outside is the army and police. Some ambulances have left the hospital too – here we go again."
Comments on Facebook include, "Is everyone OK? I don't know how much more of this my nerves can take."
One Twitter user said: "TV fell down in that one but it's still going so everything is fine!"
Meanwhile Geoscience Australia also reported a 5.4 magnitude quake centred near Bowen in Queensland at 5.21pm yesterday. There were no initial reports of damage.
The Christchurch quake struck just 28 minutes later.
The city remains devastated following the previous quake, which claimed an estimated 181 lives. It followed a magnitude 7.1 quake last September 4.
- SUSAN PEPPERELL, SUNDAY STAR-TIMES and NZPA