Japan's nuclear crisis has deepened. A fresh fire broke out at a reactor of quake-hit Fukushima No 1 nuclear power plant early this morning. A Tokyo Electric Power, TEPCO spokesman told reporters that smoke is coming out of the roof of the number-four reactor at the plant. A blaze and explosion hit the same reactor yesterday, causing a crack in the roof.The government has confirmed damage to part of the container shielding the number-two reactor at Fukushima, 250 kilometres northeast of Tokyo.Japan is frantically working to avert a nuclear meltdown after Friday's massive earthquake and tsunami that cut power to the ageing plant and knocked out cooling systems.The hydrogen explosions at No.2 and No.4 reactors yesterday prompted the government to announce that the radiation has reached harmful levels. TEPCO, which operates the plant, said, the problem could develop into a critical “meltdown” situation after part of the No.2 reactor's container vessel damaged following the explosion. All the four plants at Fukushima are reported to be in critical stage as the core of the No 1, 2 and 3 reactors are believed to have partially melted.Amid fears that the radiation from the affected nuclear reactors will move towards capital Tokyo, people mostly stayed indoors, tourists cut short vacations and scores of foreigners working in the city prepared to leave. Japanese Prime Minister Naoto Kan, in a nationally televised address, warned that the radiation has already spread from the crippled reactors and there is a very high risk of further leakage. He asked an estimated 1.4 Lakh people living within 30 kms of the facility to remain indoors and conserve power. Residents within a 20-km radius of the plant have already been ordered to vacate the area. Authorities have also announced a 30-kms 'no fly-zone' around the site to stop aircraft spreading the radiation. A 6.4 magnitude earthquake was also felt yesterday in the Japanese capital shaking buildings. Over 2,000 bodies were found yesterday on two shores in Miyagi Prefecture, the worst hit by Friday's earthquake and Tsunami.