Power was restored to most areas of Miyake Island on Wednesday after the essential personnel who remain on the volcanic island went 21 hours without electricity, the Tokyo Metropolitan Government said.

The resumption should forestall the failure of all telephones, including cellphones, on Miyake as well as on Kozu, Mikura and Aogashima in the Izu Island chain, which had been expected today.

The Ako district, however, remained blacked-out.

Power on the island, about 200 km south of Tokyo, was cut off Tuesday night after the metropolitan government ordered personnel in charge of electricity services to seek shelter following warnings of heavy rain and mudslides.

Subsequent slides blocked roads and stranded village and emergency officials who have stayed on the island.

While the Meteorological Agency has maintained its warning of heavy rain for the island, the metropolitan government got power flowing again after the weather improved Wednesday morning.

About 340 people, including village and metropolitan government officials, are still on the island to oversee essential services and continue monitoring the volcanic activity of Mount Oyama, which erupted again Aug. 29.

The evacuation of all the island's residents, some 3,850 people, was completed Monday amid fears of massive pyroclastic flows.

Authorities plan to start repair work after examining damage caused by the previous mudslides. They will also install more seismometers and other observation devices on the island.