A car is trapped in the middle of the road in a sink hole caused by liquefaction in the Christchurch suburb of Parklands after an earthquake struck Dec 23, 2011. An earthquake of 5.8 magnitude struck near the New Zealand city of Christchurch on Friday, New Zealand's civil defence said, prompting the evacuation of some public buildings and sending goods toppling from shelves.[Photo/Agencies]

WELLINGTON - New Zealand's earthquake- battered second city of Christchurch was shaken by a series of tremors Friday with four measuring at least magnitude 5.0 on the Richter scale.

The first large jolt, measuring 5.8, struck at 1:58 pm and was followed by a large aftershock, measuring 5.3 at 2:06 pm, New Zealand's GeoNet monitoring service reported.

The first quake was centered 20 km northeast of the port of Lyttleton, near Christchurch, at a depth of 8 km, and the second was 20 km east of Christchurch at a depth of 10 km, according to GeoNet.

A magnitude 6.0 tremor struck at 3:18 pm, at a depth of 6 km, centered 10 km north of Lyttleton, followed by a magnitude 5.0 jolt at a depth of 10 km and centered 20 km northeast of Lyttleton.

The New Zealand Police said there were no reports of serious or widespread damage or injury during the quakes, which struck two days before Christmas on one of the busiest shopping days of the year.

A partly demolished building and a vacant house had collapsed, said a police statement.

The quakes caused "major holes" on at least one road and " significant flooding and liquefaction" in other areas.

Police were conducting an aerial survey to check for damage and a rockfall and power blackouts had been reported, said a statement from Christchurch city council

Radio New Zealand reported that 19 people required medical treatment, although their injuries were all minor, according to ambulance services.