Japan nuclear threat raised to level seven, the same as Chernobyl

The Japanese authorities have raised the measure of severity of their nuclear crisis to the highest level.

They have reassessed the damage at the Fukushima nuclear plant following last month's massive earthquake and tsunami.

The incident has now been rated level seven, only used previously for the Chernobyl disaster in 1986.

But a spokesman said radiation leakage was still only a tenth of that from Chernobyl.

Rachel Harvey reports.