TOKYO -- An earthquake with a preliminary magnitude of 7.6 struck northeastern Japan late Monday night, triggering a tsunami warning for wide areas along the Pacific coast, the country's weather agency said.

The temblor occurred at 11:15 pm local time at a depth of 50 km, measuring upper 6 on Japan's seismic scale of 7 in the hardest-hit areas, said the Japan Meteorological Agency (JMA).

The agency has issued a tsunami warning for the coastal areas of Hokkaido, Aomori, and Iwate prefectures, with waves up to 3 meters expected.

The epicenter was located off Aomori Prefecture's eastern coast at a latitude of 41.0 degrees north and a longitude of 142.3 degrees east, according to the JMA.

A tsunami advisory has also been issued for Miyagi and Fukushima prefectures following the powerful quake.