A tsunami as high as three metres (10 feet) could hit Japan’s northeastern coast after an earthquake with an estimated magnitude of 7.6 occurred offshore at 11:15 p.m. (1415 GMT), the Japan Meteorological Agency (JMA) said.

Tsunami warnings were issued for the prefectures of Hokkaido, Aomori and Iwate, and a tsunami of 40cm had been observed at Aomori’s Mutsu Ogawara and Hokkaido’s Urakawa ports before midnight, JMA said.

The epicentre of the quake was 80 km (50 miles) off the coast of Aomori prefecture, at a depth of 50 km (30 miles), the agency added.

Japan is one of the world’s most earthquake-prone countries, with a tremor occurring at least every five minutes.