Anti-nuclear protests take place in Japan

Two weeks after an earthquake and tsunami hit Japan, the country's prime minister, Naoto Kan, has said the situation at the Fukushima nuclear plant remains ''grave and serious''.

Fukushima's operators have said water at one reactor was 10,000 times more radioactive than normal, raising fears that its core is damaged.

Anti-nuclear protests have been taking place in Tokyo as an investigation is under way to establish the source of the radiation leak.

The BBC's Rupert Wingfield Hayes reports.