A powerful earthquake measuring 6.7 on the Richter scale hit the northern Japanese island of Hokkaido early Thursday killing at least eight people.

While no tsunami warning was issued, the Japan earthquake was followed by a number of aftershocks triggering landslides that buried multiple houses.

The relatively shallow quake struck 62 kilometres (39 miles) southeast of the regional capital of Sapporo.

Rescue work is underway to search for the missing.

According to the Japan Meteorological Agency (JMA), the major temblor was centred in the Hokkaido prefecture at 3.08 am (Japan time). The epicentre was at a latitude of 42.7 degrees north and a longitude of 142.0 degrees east, and at depth of 40 km.

Of the dozens of aftershocks that followed, one recorded a preliminary magnitude of 5.4 that hit the prefecture three hours later.

Japan’s Nuclear Regulation Authority said the Tomari nuclear power plant operated by Hokkaido Electric Power Co. lost an external power source, and an emergency power supply system was currently cooling a spent fuel pool of its reactors.

The nuclear watchdog said no abnormality had been confirmed in radiation levels around the plant.

The JMA said there might be a slight sea-level change in Japan’s coastal areas because if the quake.

Police said they had received multiple reports of injuries. In Sapporo, the capital city of Hokkaido prefecture, 53 people were reported injured.

A number of houses collapsed, and rescue work is underway for those possibly buried under them, according to local media reports.