Japan will widen the evacuation area around the Fukushima Daiichi nuclear power plant outside the current 20 km (12 mile) exclusion zone.
According to AFP, government spokesman Yukio Edano said within one month people will be told to leave the village of Katsurao, Namie town and Iitate village as well as part of Kawamata town and Minamisoma city, due to long-term health concerns.
"The government has designated for evacuation areas where the radiation exposure level is expected to reach 20 millisieverts per year," Edano said.
Edano, who had earlier warned the government was considering a widening of the area, said a uniform extension of the zone was not appropriate. "There are some places where cumulative levels of radiation are increasing depending on climate and geographical conditions even outside of the 20 km radius circle," he said.
Edano said the situation at the nuclear plant had not deteriorated and the widening of the zone reflected only concerns over the effect of long-term exposure.
"If you continue living in the areas for a long time, like six months or one year, the cumulative radiation levels may get even higher. This evacuation will impose enormous burdens on residents of these areas, but they are required to move to other places under this evacuation. It is preferable that they evacuate within about one month."
Meanwhile, Fukushima Daiichi operator Tokyo Electric Power (Tepco) evacuated workers from the stricken plant following a magnitude 7.1 earthquake that hit northeast Japan on Monday. Tepco said there were no irregularities at the plant.