Prime Minister Naoto Kan said the government is doing its utmost to ensure the public's safety and minimize the damage, including dispatching the Self-Defense Forces for rescue operations, following the massive earthquake and tsunami that hit the Tohoku region Friday.

"I ask the people to act with calm and continue to listen carefully for information via television and radio," Kan said in a televised address. He said some nuclear power plants stopped operations but the government detected no radiation leaks.

Eleven reactors automatically shut down at the Onagawa plant, Fukushima No. 1 and No. 2 plants and Tokai No. 2 plant, the Ministry of Economy, Trade and Industry said, adding there were no immediate reports from monitoring posts of fires or other abnormalities near the plants after the 2:46 p.m. quake.