The quakes ranged in magnitude from 5 to 6, the U.S. Geological Survey reported. That is strong enough to damage badly constructed buildings.
The first quake was felt early Friday afternoon. The most recent struck at 6:37 a.m. Saturday, local time.
A few injuries, most of them minor, were reported, The New Zealand Herald reported.
Mayor Bob Parker said the physical damage also appeared minimal. But he said the stress is severe for people still coping with the aftermath of an earthquake that killed 180 people and caused widespread destruction and subsequent aftershocks.
"Many of them just sitting around and in tears -- you just can't understand the ongoing stress," he told TVNZ. "We were just getting over that feeling, I think, and it sets people back."
Thousands of people lost electricity. The airport was shut down for inspection, disrupting holiday travel.
Sarno Yambasef, his wife and children moved into a neighborhood last year where liquefaction -- earth turning to mud -- has been a major problem in every quake. He said the house "seemed to lift off its piles" with the first temblor Friday.
"We don't know what to do, but we can't stay here," Yambasef told the Herald. "We were excited about a bigger house for our children, but now we want out. This really is the final straw."
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