Two Japanese scientists and a Japanese-born American have won the Nobel Prize in physics for inventing blue light-emitting diodes.

Isamu Akasaki and Hiroshi Amano of Japan and US scientist Shuji Nakamura have won the Nobel Prize in physics for the invention of blue light-emitting diodes - a new energy efficient and environment-friendly light source.

Toxic gases and ash have forced recovery teams to suspend their search at the still-erupting Mount Ontake volcano.

The Japanese government has set its first radiation safety standards for fish after a tsunami-ravaged nuclear plant reported radioactive contamination in nearby sea water measuring several million times the legal limit.