The latest natural disaster hittingJapan during one of the country's most hard summers killed at least four people, with more than 30 still missing. The number missing had earlier been put at 19.
Earth is exposed in many parts of the mountains in Atsuma. The collapsed remains of what appeared to be houses or barns were scattered about. It may take a week to restore power fully to all residents, he said.
The quake left nearly three million people without power after damage to a major thermal plant supplying the region, with Industry Minister Hiroshige Seko saying it could take "at least a week" for supply to be restored.
All trains across the island were also halted.
Employees of the local office of the JMA were heading to the Atsuma area to locate seismic meters that failed to transmit the quake's intensity in its immediate aftermath.
Moreover, Hokkaido's main airport, New Chitose Airport, was shut in the aftermath of the quake, which struck nearby.
The International Tsunami Information Centre said there was no tsunami threat.
More than 4,000 defence force soldiers have been deployed to help with rescue operations, CNN quoted Prime Minister Shinzo Abe as saying.
The landslide engulfs houses in Atsuma town, Hokkaido.
The magnitude 6.7 natural disaster struck the island of Hokkaido at 3:08 a.m., damaging homes, roads and a coal-fired power plant, officials said.
A Hokkaido Electric spokesman said the utility was not receiving any supplies from the island of Honshu to the south - home to Tokyo, Osaka and Nagoya - despite there being a 600 megawatt connection for transferring power from the coast of Japan's main island.
It registered a strong 6 on Japan's 7-point quake scale. The government said later in the day that supplies had been restored to about 340,000 homes.
A landslide along a long ridge in the rural town of Atsumi could be seen in aerial footage from public broadcaster NHK.
The news service reports that the quake triggered a blackout across a wide area in Hokkaido.
Power was cut in cities including Sapporo, Hakodate and Tomakomai.
Aftershocks were continuing Thursday morning, and could pose a risk for the next week, according to the Japan Meteorological Agency, which warned residents of the increased risk that buildings could collapse near the epicenter of the original quake.
A landslide in Atsuma town, Hokkaido prefecture, caused by the powerful quake that hit the Japanese island of Hokkaido. It set off a tsunami that devastated communities along the Pacific coast and killed almost 20,000 people.
A doctor in Abira, the town next to Atsuma said: "Without electricity, there's nothing I can do except to write prescriptions".
Both JMA and the Pacific Tsunami Warning Center said there is no threat of a tsunami from Thursday's quake.