Millions of households affected by Friday's horrific temblor and tsunami are experiencing interruptions to water, gas and electricity supplies, and exactly when they will be restored is uncertain.
On Saturday, Tokyo Electric Power Co. warned that blackouts could strike in many areas, not just in the zone of devastation, because damage to power-generation facilities has left electricity in short supply.
Tepco called on both companies and individuals to save power and sought help from other utilities in supplying electricity. In addition, it decided to cancel a plan to suspend power supplies for about three hours on a rotational and regional basis Sunday but said it might be reconsidered for Monday.
Tepco, operator of the Fukushima No. 1 nuclear plant, opened valves to release pressure from inside the container housing the reactors, a move that led to the release of a small amount of radioactive steam.
Industry minister Banri Kaieda also issued a plea to restrict electricity use.
As of Saturday noon, electricity at about 5.1 million households in the Tohoku and Kanto regions was still out. About 4.1 million are within Tohoku Electric Power Co.'s operation, and the utility is trying to resume safe operations, but cannot predict when this will occur.
According to Tohoku Electric, electricity in four prefectures was totally cut off: Miyagi with 1.38 million households, Aomori with 790,000, Iwate with 750,000 and Akita with 530,000.
Almost all areas where electricity is supplied in Yamagata Prefecture, or some 450,000 households, were also out, and 190,000 houses in Fukushima Prefecture also experienced a blackout.
As for the Kanto region, Tepco said about 1 million households in three prefectures, 640,000 in Ibaraki, 210,000 in Tochigi and 130,000 in Chiba, are without electricity, while the recovery is under way. The supply for Tokyo and Gunma, Saitama, Yamanashi and Shizuoka prefectures has been restored.