Nuclear safety officials in Japan fear the core of a reactor at the Fukushima Daiichi nuclear power plant may have cracked, causing a leak of high levels of radiation. Growing uncertainty over the state of the stricken reactor prompted the government to tell people living within a 12-19 mile (20-30km) radius of the plant to consider leaving their homes temporarily.
The government's chief spokesman, Yukio Edano, said 130,000 residents in the area had been encouraged to leave to improve their quality of life, not because their health was at risk. The nuclear emergency, 150 miles north of Tokyo, has caused severe disruption to business, supply routes and other services in the area.
On Thursday, three workers were exposed to radiation after stepping in contaminated water in the turbine building of the No 3 reactor. They were trying to cool the crippled reactor when the accident occurred.
"The contaminated water had 10,000 times the amount of radiation as would be found in water circulating from a normally operating reactor," said Hidehiko Nishiyama, a spokesman for Japan's nuclear safety agency. "It is possible that there is damage to the reactor."