An earthquake measuring 5.1 on the Richter scale occurred near New Zealand South Island city of Christchurch on Friday morning. There were no reports of injures or damage.

The quake occurred at 5:39 a.m.. local time (17:39 GMT Thursday) , and was centered 40 km west of the city, at a depth of 12 km, said New Zealand Institute of Geological and Nuclear Sciences (GNS) .

The inner-city red-zone in Christchurch was closed. Canterbury Earthquake Recovery Authority said it is checking a cross-section of buildings for damage.

GNS seismologists said the earthquake was felt along the east coast of the South Island from North Canterbury to Dunedin.

GNS said the tremor was centered on the Greendale fault, which was at the center of the magnitude 7.1 quake on Sept. 4 last year.

GNS Duty Seismologist Caroline Holden said a few more magnitude 4 quakes are expected in the coming days.