Already scrambling to control an overheated nuclear reactor and rescue residents in areas engulfed by tsunami, the government is also rushing to reassure a public being misled by online chain letters and other information.
Over the weekend, it was reported that an anonymous sender initiated an online alert campaign telling people to carry umbrellas and raincoats because "the explosion at Cosmo Oil refinery (in Chiba Prefecture) has released a poisonous substance into the atmosphere that will come down with rain."
The sender, citing his or her brother-in-law as the source, warned people to stay inside unless absolutely necessary.
Cosmo Oil released a statement saying the tanks that exploded contained liquefied petroleum gas and the likelihood of a threat to health is "extremely low."
Chief Cabinet Secretary Yukio Edano also warned that such misleading e-mail letters "stir up unnecessary anxiety" and that senders should refrain from sending them.
But some Twitter messages on Sunday went further and reported that an anonymous government source confirmed that radioactive particles had reached Tokyo — a claim that experts say is impossible because the reactors in Fukushima Prefecture are "under control."