Japanese Chief Cabinet Secretary Yukio Edano said Friday that the government has ordered residents in areas between 20-km and 30-km ring of the crippled Fukushima No.1 nuclear plant to evacuate due to accumulated radiation.

Residents of more localities outside the 30-km radius should be prepared to evacuate in case of emergency, he said.

About 70,000 to 80,000 local residents have been ordered to evacuate from areas within 20 kilometers from the plant.

Japan's evacuation directives escalated step by step as workers are still struggling to regain control of the crippled plant after a devastating earthquake and tsunami hit northeastern regions of Japan on March 11, according to Xinhua.

Japanese Prime Minister Naoto Kan Thursday announced that areas 20 kilometers from the Fukushima nuclear power plant were designated as the no-entry zone during a visit to Fukushima Prefecture, Kyodo reported.

From Thursday midnight, the Japanese government sealed off the 20-kilometer radius of the Fukushima plant to prohibit unrestricted entry.

Earlier the plant operator Tokyo Electric Power Co. said that it will take about six to nine months to fix the troubled reactors at the plant.