CHRISTCHURCH, New Zealand - A 5.3-magnitude aftershock struck New Zealand South Island city of Christchurch on Saturday, causing damage to buildings and roads.

Christchurch City Council said there are new reports of liquefaction and flooding in the eastern suburbs following Saturday's 5.3-magnitude aftershock.

New Zealand Institute of Geological and Nuclear Science reported the aftershock hit at 05:49 pm local time (0549 GMT) at a depth of 11 km and was 20 km south-east of Christchurch.

There was also a 4.1-magnitude aftershock at 08:40 pm local time.

There has been new liquefaction and flooding in the eastern suburbs, which was badly damaged in the earlier earthquakes.

The Strategy Building on Victoria Street, just north of the city center, tilted during the aftershock, and extra cordons have been placed around it.

Montreal Street has been closed, and a diversion is in place.

There are also reports of new rock falls in the Sumner and Redcliffs area.

Some power lines are down over a digger at the Stanmore shops at the corner of Stanmore Road and Worcester Street and the intersection is closed.

Christchurch mayor Bob Parker once again urged people to conserve water after the aftershock broke some pipes and water mains.

Immediately following the aftershock, about 20,000 customers lost power, but power had been restored by 08:00 pm local time.

Phone services were disrupted for a time and some mobile phone sites were forced to run off battery power.

The aftershock was one of the biggest aftershocks since the 6.3- magnitude quake hit Christchurch on February 22, which claimed 181 lives.

The biggest aftershock since the devastating 6.3-earthquake was on the same day of that quake, measuring 5.7. There was also a 5.5- magnitude quake on that day.

Special Coverage: Deadly quake hits New Zealand