Wellington - New Zealand's earthquake-battered city Christchurch was still shaking on Monday as it counted the cost of a big aftershock at the weekend which left an already condemned office block leaning dangerously and toppled boulders off cliffs onto suburban houses.
Two aftershocks were recorded early on Monday following four the previous day and 10 on Saturday, including one of magnitude 5.3, the biggest to hit the stricken city since a 6.3 tremor devastated the city centre - already severely damaged by a 7.1 quake in November - on February 22.
A geologist said a significant number of houses on the side of the Port Hills overlooking the city, where more than 400 damaged homes had already been evacuated, may have to be abandoned after up to 150 new rockfalls.
A seismologist warned residents of New Zealand's second-largest city, whose nerves have been wracked by constant tremors for more than five months now, that the aftershocks could continue for a year.
Streets around a five-storey office block in the city centre which were re-opened only a week ago were cordoned off again after Saturday's big aftershock shifted it 15cm and left it hovering dangerously.
Civil defence officials said the building, which was already scheduled for a controlled demolition, would have to be brought down urgently before it collapsed onto surrounding streets.
About 20 000 homes lost power for up to three hours and 12 water mains burst after Saturday's 5.3 aftershock, leaving a new layer of silt brought up by liquefaction of the Earth over large areas of the suburb of Bexley and its surrounds.
The Department of Building and Housing said it had received about 1 600 inquiries for temporary portable houses it is building in suburban parks for residents who cannot return to their quake-damaged homes.
It estimated that up to 10 000 people could need temporary accommodation in the fast-approaching winter. - Sapa-dpa