Magnitude 7.2 quake strikes off Japan's northern coast and triggers a tsunami alert

A powerful earthquake struck off the coast of northern Japan on Monday, triggering a tsunami alert, the Japanese Meteorological Agency said.

The agency said the magnitude 7.2 quake struck off the coast of Hokkaido, near the coastal city of Aomori with an epicenter about 50 kilometers (about 30 miles) below the sea surface.

It issued an alert in the region for a tsunami of up to 3 meters (up to 10 feet).

Nuclear power plants in the region were conducting safety checks, public broadcaster NHK reported.