TOKYO — Beleaguered Tokyo Electric Power on Monday said it had begun a power outage in an area covering some parts of Tokyo and eight prefectures, affecting around 333,000 households.

Authorities have announced plans for scheduled rolling power cuts in areas served by TEPCO to make up for the loss of power from crippled nuclear plants, including the Tokyo utility's troubled Fukushima Number One facility.

The outage began at around 5 pm (0800 GMT) and was expected to last around two hours. A TEPCO official told AFP that affected areas included some municipalities in Ibaraki prefecture, east of Tokyo, and Shizuoka southwest of the capital.

The power outs did not affect central Tokyo where people swarmed local convenience stores, stripping shelves of water, toilet rolls, bread, flashlights and instant noodles to take home.

"Bread and cup noodles are selling out all the time," said a FamilyMart convenience store manager in Tokyo.

"Customers are bulk buying as many as 10 or 20 cup noodles at one time. It's first-come-first-served. All the bread sold out early this morning."

At a Lawson convenience store in Tokyo, the empty shelves were explained by a simple note.

"We have prioritised on supplying food to the areas affected by the earthquake."

Japan, which records 20 percent of the world's major earthquakes, generates about 30 percent of its power from 54 nuclear plants. After the quake and tsunami, 11 were shut down.

An explosion rocked a building housing a nuclear reactor at a TEPCO's quake-damaged Japanese power plant Monday, the second such blast in two days, and the cooling system failed at a third reactor.

The new troubles at the Fukushima Number One plant, located 250 kilometres (120 miles) north of Tokyo, stalled Japan's efforts to secure the atomic power facility in the wake of Friday's massive quake.

With additional reporting by Raw Story.