Wellington - A series of nine earthquakes - two of more than magnitude-5- hit New Zealand's quake-ravaged city of Christchurch in the first seven hours of Monday.
There were no immediate reports of damage, but a double shock 12 seconds apart, with the larger reaching magnitude-5.5, triggered an automatic power shut-off to 10,000 homes.
The first tremor, measuring 3.9, hit at 1:27 am (1227 GMT Sunday), followed by two more measuring at more than magnitude 5 and four surpassing magnitude 4 before 7 am, seismologists at the state GeoNet organization reported.
"People just want a good night's sleep at the moment and when you're having a whole night of it, it's very, very difficult to get some sleep," Roger Sutton, head of the Canterbury Earthquake Recovery Authority, told Radio New Zealand.
He said there did not appear to be any significant further damage to the city, which has been racked by quakes since September 2010, including one in February that killed 181 people.
Sutton urged residents to check on neighbours and make sure that people were coping.//DPA