A powerful earthquake with a 7.3 magnitude struck off New Zealand early Tuesday, the US Geological Survey said, but there were no early reports of casualties or significant damage.

The quake struck at a depth of 35 kilometers (22 miles) under the seabed off the remote Kermadec islands at 03:09 a.m. (1519 Monday GMT), the USGS said.

No tsunami warning was immediately issued.

Earthquakes are frequent in New Zealand, where the boundaries of continental plates meet as part of the Pacific "Ring of Fire", causing earthquakes and volcanic activity.