CHRISTCHURCH, New Zealand, Sept. 8 (UPI) -- Aftershocks knocked out power in Christchurch, New Zealand, Wednesday, delaying repairs to the city's earthquake-damaged waterlines, officials said.
Officials said the rumblings reversed some of the work done Tuesday, and more parts of the city were without water, Radio New Zealand reported.
The 5.1-magnitude and 4.1-magnitude aftershocks followed last week's 7.1-magnitude earthquake.
The Civil Defense agency warned more aftershocks could occur, and an aftershock as strong as a magnitude-6 could be expected.
Civil Defense Minister John Carter told Parliament Wednesday the recovery would take months instead of weeks, Radio New Zealand said.
Carter also said demands for assistance would rise and more welfare centers likely would be needed.
Onno Mulder, head of council-controlled contractor City Care, says the supply and wastewater problems could last at least six months. Some streets have up to 15 breaks in their water mains, he said.
Officials extended a state of emergency in Christchurch by seven days. The emergency, declared on Wednesday, affects only the city, not the broader Canterbury area.
The Treasury Department pegged the economic effect of the earthquake at $4 billion. The department said the estimate includes costs to businesses as well as households.
