Rescue workers search for survivors from a house damaged by a landslide caused by an earthquake in Atsuma town in Japan's northern island of Hokkaido, Japan, in this photo taken by Kyodo September 6, 2018. Kyodo/via REUTERS

TOKYO (Reuters) - Restoring full power across Japan’s northern island of Hokkaido will take at least a week after a powerful earthquake struck early in the day, damaging its largest fossil fuel power plant, Trade and Industry Minister Hiroshige Seko said on Thursday.

The government is seeking to restore partial power to some areas as soon as possible once Hokkaido Electric Power Co 9509.T restarts its Sunagawa coal-fired plant, Seko said.

Hokkaido Electric had been aiming to first restart its Tomato-Atsuma plant, which supplies about half the island’s power, but repairs are projected to take at least a week after the breakout of a fire from the No.4 unit’s turbine and boiler damage at units No.1 and No.2, Seko said.

Hokkaido Electric has restarted four hydropower units with a total capacity of 300 megawatts (MW) and will restart the 250-MW Sunagawa coal-fired plant on Thursday, he said.

The company will also restart its 350-MW coal-fired Naie plant, oil-fired 700-MW Date plant and 700-MW oil-fired Shiriuchi plant from as early as Friday, Seko said.

The restoration of 2.9 gigwatts (GW) of power is expected to be possible by the end of Friday, including 600-MW of power coming across from the mainland, he said.

Peak power demand in Hokkaido, however, reaches 3.8 GW, so the restoration of all power across the island should take at least another week, Seko said.

Hokkaido Electric said this is the first time since its establishment in 1951 that power has been lost across the entire island.