SOMA, Japan – A fire broke out at a nuclear reactor again Wednesday, a day after the power plant emitted a burst of radiation that panicked an already edgy Japan and left the government struggling to contain a spiraling crisis caused by last week's earthquake and tsunami.


The outer housing of the containment vessel at the No. 4 unit at the Fukushima Dai-ichi nuclear complex erupted in flames early Wednesday, said Hajimi Motujuku, a spokesman for the plant's operator, Tokyo Electric Power Co.


On Tuesday, a fire broke out in the same reactor's fuel storage pond — an area where used nuclear fuel is kept cool — causing radioactivity to be released into the atmosphere. Tokyo Electric Power said the new blaze erupted because the initial fire had not been fully extinguished.


About three hours after the blaze erupted Wednesday, Japan's nuclear safety agency said fire and smoke could no longer be seen at Unit 4, but that it was unable to confirm that the blaze had been put out.


Radiation levels in areas around the nuclear plant rose early Tuesday afternoon but appeared to subside by evening, officials said. But the unease remained in a country trying to recover from the massive disasters that are believed to have killed more than 10,000 people and battered the world's third-largest economy.