A powerful natural disaster of magnitude 6.6 left residents trapped inside their homes as a landslide blocked roads, engulfed buildings and led to widespread power cuts on Japan's northern island of Hokkaido in the early hours of Thursday.
Landslides along a ridge in the town of Atsuma have wiped out several homes and officials fear that residents may be trapped inside.
Almost two million people live in Sapporo.
At least 32 people were missing and 120 were injured in Hokkaido after the magnitude 6.7 quake, NHK said.
All thermal power stations automatically stopped following the magnitude-6.7 quake, according to Hokkaido Electric Power Co.
Industry Minister Hiroshige Seko said it would take "at least a week" for power to be restored to almost three million homes after a fire in the area's largest thermal plant was discovered.
The utility was trying to restore some power from hydroelectric and other fossil-fuel sources on Thursday and aimed to bring other plants on line by Friday, industry minister Hiroshige Seko told reporters.
See how the news unfolded here.
Prime Minister Shinzo Abe said officials hoped to reopen Kansai Airport for domestic flights on Friday.
A magnitude 6.7 quake struck southern Hokkaido soon after 6am NZT, at a depth of 40 kilometres, Japan's Meteorological Agency said.
The quakes - magnitude-6.6 and -5.3 - struck Tomakomai, the fifth largest city in the Hokkaido area, according to the United States Geological Survey (USGS). Kirin Beer and Sapporo Beer both said factories were shut by the power outage, although they said no structural damage was found.
Local news has reported a blackout across a wide area in Hokkaido.
Footage on NHK national television showed the moment the quake struck Muroran, with its camera violently shaking and all city lights going out a moment later.
In Tokyo, the central government said the Self-Defence Forces will dispatch 25,000 personnel for relief operations at the request of the governor of Hokkaido.
The powerful quake and tsunami in March 2011 that hit northeast Japan destroyed both external and backup power to the Fukushima Dai-ichi nuclear plant, causing meltdowns.
They warned residents about increased risks of collapse among buildings near the epicenter.
A police officer controls the traffic during a blackout following a strong quake in Sapporo, northern Japan early Thursday, Sept. 6, 2018.
On Mar 11, 2011, a devastating 9.0-magnitude quake struck under the Pacific Ocean, and the resulting tsunami caused widespread damage and claimed thousands of lives. Seismologists have said another such quake could strike the city at any time.