Sony operates several plants in the region and has yet to release information on when they might restart production.

Several companies have announced plans to temporarily suspend production at some domestic factories. They include Toshiba, Panasonic and Sharp. The factories are either impacted by the earthquake or unable to get components because of disruptions to their supply chain.

"This is the worst crisis in Japan's 65-year postwar history," Prime Minister Naoto Kan said in a televised news conference. "I'm sure that we will be able to overcome the crisis."

Rescue teams from around the world are pouring into Japan and charities have begun raising money for those affected.

Sony and Panasonic each said they would donate ¥300 million (US$3.7 million) to relief efforts. Sony said it would also provide 30,000 radios to those affected.