New Zealand's earthquake-devastated southern city of Christchurch has been  rocked by yet another huge quake, the most violent and destructive series of  aftershocks to hit since the February 22 disaster killed 181 people.  Buildings shook and liquefaction bubbled up through the streets in the 6.0  quake, which hit about 2.20pm (1220 AEST).  It followed a 5.5-magnitude quake that hit about 1pm (1100 AEST) and was centred 10km southeast of Christchurch at a depth of 11km.  An earlier measuring 4.4-magnitude hit about half an hour earlier.  GNS Science spokesman Kevin Fenaughty said the latest aftershock was 'over  six' in magnitude.
The GNS Science website put the quake at 6.0, at a depth of 9km, and said it was centred 10km south-east of Christchurch. Emergency Services say there were no reports of deaths but have confirmed  that six people have been taken to Christchurch hospital with moderately serious  injuries.  'The injuries were as a result of falling building material,' a spokeswoman  for St John Ambulance told Chan6es.  'We had several ambulances operating in the city and some on stand by  straight after the earthquake.
 Two people were rescued from a church in the centre of town and another empty  building, which was partially damaged in the February quake, completely  collapsed in this latest shake.  Christchurch Mayor Bob Parker told Radio New Zealand the latest quake was  bigger than the 1pm one.  'Thank God we had evacuated the (city's already damaged) red zone.  'We are being enveloped with dust. It is very, very scary.  'There has been a report of a further collapse of the remnants of the  Christchurch Cathedral.
'We need to get a picture of what is really happening and to make a call on  where we need to send our essential services,' he said, cutting the interview  short.  Fire Service spokesman Ian Lynn said crews had been called out to about 38  incidents, including a house fire, broken water mains, and liquefaction. Rocks have been seen falling from the hills in the coastal suburb of Sumner, 
 while the University of Canterbury, a shopping mall and a supermarket had been  evacuated.  There have been reports of liquefaction bubbling up from the ground in the  central Christchurch suburb of Richmond and the outer suburbs, the NZ Herald 
 reported.  There have also been reports of power loss and downed phone lines around Christchurch.