Awwal 17, 1432 H / April 21, 2011, SPA -- Japanese Prime Minister Naoto Kan said Thursday that the government was banning entry into the 20-kilometre exclusion zone around a damaged nuclear power plant, according to dpa. The move came after some evacuated residents have been returning to their homes to fetch belongings and check on their residences despite radiation leaks from the plant. Kan announced the decision, which was to take effect at midnight, during talks with Fukushima Governor Yuhei Sato at the Fukushima prefectural office. Sato told reporters he urged the premier to thoroughly explain the move to the municipalities within the legally binding "caution areas." Many residents left the area around the Fukushima Daiichi Nuclear Power Station, 250 kilometres north-east of Tokyo, after it was crippled by the March 11 earthquake and tsunami and began leaking radioactive material. The government said it was to allow evacuees to return for short, monitored visits because the plant's operator, the Tokyo Electric Power Co (TEPCO), said it would take six to nine months to bring the reactors under control. Chief Cabinet Secretary Yukio Edano said the government would allow one person per family to return for up to two hours, but he added evacuees could return many times. They would be required to wear protective clothing and carry equipment to measure their exposure to radiation, he said. The government was to implement the measure in a few days but those visits would be stopped in one or two months, Edano said. Many evacuees expressed reservations about the move to further restrict access to the affected area. "We cannot see the impact of radiation so the government's measure cannot be helped," Akiyoshi Fushimi, an evacuee from Okuma, was quoted by Kyodo News agency as saying, "but telling us not to enter is unjustified when they do not even inform us of figures for local radiation dosage." The government told residents within 20 kilometres of the plant to evacuate soon after the tsunami, but there was originally no formal order to vacate the area. Those living 20 to 30 kilometres from the six-reactor plant have been advised to leave voluntarily or stay indoors as much as possible. The leaks of radioactive material occurred after the reactors' cooling systems were crippled in the disaster last month, causing overheating, partial meltdowns and explosions. TEPCO said Thursday that radioactive substances that leaked into the sea from reactor number 2 totalled an estimated 5,000 terabecquerels, 20,000 times more than the annual limit allowed for the plant. The leaks were noticed April 2 and stopped April 6. TEPCO said the radioactive substances were in an estimated 520 tons of high-level radioactive water released from the plant. The sea contamination was far lower than the 370,000 to 630,000 terabecquerels of radioactive material estimated to have been released into the atmosphere from the plant since the crisis began, the Kyodo reported.