(EFE).- A powerful 7.8 magnitude earthquake rocked the South Island of New Zealand on Sunday, without reports on casualties or declaring a tsunami alert by the authorities.

The tremor occurred at 23:02 local time (11:02 GMT) and had its epicenter at the depth of 10 kilometers (6.21 miles), according to the United States Geological Survey which records seismic activity worldwide.

Incident response teams are currently assessing the earthquake damage, which could have affected some houses in the town of Cheviot, located nearby the epicenter of the quake, according to the New Zealand Herald newspaper.

New Zealand’s Ministry of Civil Defense and Emergency Management confirmed that tsunami waves have already been generated following the 7.8 magnitude earthquake that hit the South Island of New Zealand earlier on the day, which was followed by several aftershocks. Casualties and damages are yet to be reported.

“A tsunami has been generated. Waves are expected to arrive at the Chatham islands immediately – anyone in the Chathams should move to high ground urgently,” the ministry confirmed in a statement on its website.

“The first wave has arrived in the North Eastern Coast of the South Island and it may arrive in Eastern Coast of the North and South Islands of New Zealand shorly (including Wellington, Christchurch and the Chatham Islands). The first wave may not be the largest. Waves may continue for several hours. Move inland or to higher ground immediately,” the noted stressed.

The ministry also urged residents to listen to the radio and/or TV for updates and follow the instructions of the local civil defense authorities.

The Pacific Tsunami Warning Center in Hawaii issued a delayed tsunami warning after the earthquake, asking people in coastal areas of New Zealand’s South Island to move inland.

Around 14,000 earthquakes take place in New Zealand every year; however, only between 100 and 150 have sufficient power to be felt by the residents.

On February 22, 2011, at least 185 people were killed, while around 30,000 buildings were damaged due to the earthquake that took place in the city of Christchurch; registering 6.3 on the Richter scale.