Aerial footage showed rescuers with dogs walking through the destruction.
A powerful 6.6-magnitude natural disaster rocked the northern Japanese island of Hokkaido Thursday, triggering landslides, collapsing buildings, and killing at least two people with several dozen missing.
In the Hokkaido quake, more than 20 houses were flattened in Atsuma and Abira after mountain slopes collapsed over them across wide areas, leaving vegetation only on the mountain ridges.
Thirty-one people were still missing, with about 300 sustaining minor injuries, the broadcaster said. The number missing had earlier been put at 19.
However, considering the strength of the quake, the death toll was relatively light, with the majority of victims coming from the landslide in Atsuma. I thought my house was going to collapse.
Economy, trade and industry minister Hiroshige Seko said the extensive power outage was caused by an emergency shutdown of the main thermal power plant at Tomato Atsuma, which supplies half of Hokkaido's electricity.
The minister said several other thermal and hydroelectric plants were being started up but it would be some time before power was fully restored.
The quake also affected several manufacturers on the island.
Police officers and rescue workers search for survivors from a building damaged by a landslide caused by a powerful quake in Atsuma town in Japan's northern island of Hokkaido, Japan, in this photo taken by Kyodo September 6, 2018.
Japan is now reeling from a deadly typhoon, the strongest in 25 years, that struck the west of the country last week, killing at least 10 people.
Japanese Prime Minister Shinzo Abe said on Thursday that Kansai Airport will partially resume operations by the end of Friday.and added that global flights will restart as soon as they are ready.
Japan Meteorological Agency (JMA) officials said it was the largest quake to strike the district since records were first taken in 1923.
It is also coordinating with the Hokkaido Prefectural Government Crisis Management Division, the DFA said.
"The government will work together towards reconstruction while giving the top priority to saving human lives", Abe told reporters. Over 120 people were injured, while dozens more feared missing under collapsed structures.
The nuclear site suffered a power outage, but officials said it was cooling its spent nuclear fuel safely. Operator Hokkaido Electric reported no radiation irregularities at the plant, Suga told a news conference.
Farming, tourism and other services are big economic drivers on Hokkaido, which accounts for just 3.6 percent of Japan's GDP, but there is some industry.
It posed no tsunami risk, the country's meteorological agency said.
The quake's epicenter was east of the city of Tomakomai.
The blackout and landslides, triggered by the quake, paralyzed the island. Aftershocks shook the area for hours.
Japan sits on the Pacific "Ring of Fire" where numerous world's earthquakes and volcanic eruptions are recorded.
At least nine people were killed, Prime Minister Shinzo Abe said.
Houses destroyed by the landslide in Atsuma town.
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.