Major quake strikes off New Zealand's coast; tsunami warning issued

(CNN) - New Zealand was under a tsunami  warning Wednesday after a major earthquake with a magnitude of 7.8 struck off the west coast of its South Island, according to the U.S. Pacific Tsunami Warning Center.

The quake struck around 8:22 p.m. local time (9:22 a.m. UTC) and its epicenter was located 100 miles (161 km) west of Invercargill, according to the U.S. Geological Survey, which measures earthquakes around the world.

The tsunami warning, which was issued as a precaution, applies only to New Zealand. The warning center said it is not known if a tsunami was actually generated by the quake.

The temblor shook buildings in Queenstown - located about 100 miles north of Invercargill - and scared residents who ran into the streets, according to the New Zealand Herald.

The quake, which was felt across South Island, downed power and phone lines, the newspaper reported.

"It wasn't very violent, more of a rolling feel," Simon Darby, a resident of the inland town of Wanaka, told the Herald. "But it had a power about it - I ran straight outside into the carpark."