The Japanese government will prohibit people from entering an area within a 20-kilometer radius of the Fukushima No. 1 nuclear power plant, Prime Minister Naoto Kan said on April 21.

Kan announced the "no-entry" policy, which will be effective from midnight April 21, while holding talks with Fukushima ’s mayor Yuhei Sato.

Chief Cabinet Secretary Yukio Edano said at a televised press conference that only one person per family will be allowed to return for up to around two hours. They will be made to wear protective clothing and carry dosimeters.

Between 70,000 and 80,000 local residents in 10 districts in Fukushima prefecture within the 20-kilometer radius evacuation zone have already relocated to other places.

Of the 3,378 households in the 20-km radius visited by police from March 29 to April 18, 63 households remained despite government's persuasion, Edano said.

The same day, an earthquake measuring 6.0 on the Richter scale occurred off the east coast of Honshu at 10:54 local time (0154 GMT), both Chinese Earthquake Networks Centre and the US Geological Survey said.

There were no tsunami reported and no immediate report of damage. /.