Other manufacturing plants in the region remained closed today, including a magnetic plant in Kurihara which is owned by Sony Chemical & Information Device Corporation. Five other Sony group plants in Iwate and Miyagi were also affected but operations have already returned to normal levels, Instrat said.

Preliminary reports, said Instrat, indicate that buildings located near the epicenter region have sustained some damage and the earthquake triggered landslides and damage to roads and infrastructure.

Twelve people are still missing and more than 250 have been injured. Transportation was also disrupted and approximately 2,000 passengers in bullet trains were temporarily stranded after operations were suspended.

Nine airports (including Aomori, Misawa, Hanamaki, Fukushima and Sendai) were also temporarily closed for inspections but reopened soon after, the report said.

Japan deployed around 1,000 rescue and disaster officials to the affected region and hundreds of people were rescued from their cut off homes by helicopter in the main regional town of Kurihara (population of about 80,000).

Several major points of access to the hardest hit towns were virtually unreachable by road following landslides. At least 600 people living in remote areas were cut off after landslides, including 111 in Ichinoseki.

More than 200 people are staying in shelters in the hardest hit areas, where about 3,500 households are without water and about 2,800 households are without electricity, local government officials said.

Elsewhere, seven power stations were temporarily shutdown following the earthquake. As a result, power was cut off to more than 29,000 households in Iwate and Miyagi prefectures before being restored to most properties, according to the Economy, Trade and Industry Ministry.

Tokyo Electric said it had found that nearly 15 liters of wastewater containing radioactive substances had leaked within the premises of its Fukushima No. 2 plant but confirmed there was no impact on the environment.