A second hydrogen explosion in three days rocked a Japanese nuclear reactor today and fuel rods were left dangerously exposed at another unit as authorities worked to avert any catastrophic release of radiation in the tsunami zone.

Japan issued a tsunami alert today and told Pacific coast residents to flee to higher ground after a powerful earthquake hit off sparsely populated islands between northern Japan and the Russian Far East.

Residents along Japan’s Pacific coast were told to flee an impending tsunami after a powerful earthquake with preliminary magnitude 8.1 hit the Kuril islands north of Japan today.