A meltdown was threatening in three reactors of Japan's quake-stricken Fukushima 1 nuclear power plan, officials said Monday, reported DPA.
The fuel rods in the reactor cores were overheating after the cooling systems were shut down by the magnitude-9 quake and tsunami on Friday, government spokesman Yukio Edano was quoted by Kyodo News as saying.
The fuel power plant's number 2 reactor had started to melt, earlier reports said.