There was growing panic in Japan today as a third massive explosion at a nuclear power station hit by the tsunami pushed the country to the brink of catastrophe.

There was growing panic in Japan today as a third massive explosion at a nuclear power station hit by the tsunami pushed the country to the brink of catastrophe.

The government was forced to to order 140,000 residents to seal themselves indoors today as more radioactive material was released into the atmosphere by the latest explosion early this morning. 

It is another dramatic escalation in the nuclear crisis facing the country after Friday's tsunami knocked out cooling systems at the Fukushima Dai-ichi plant - leaving engineers struggling to avoid a catastrophic meltdown.

In a televised address to the nation after the third explosion in four days, Japanese Prime Minister Naoto Kan confirmed radiation had been released into the atmosphere after the latest blast at the Number 2 reactor. 

It follows explosions at Number 1 and Number 3 reactors and the Number 4 reactor, which was shut down when the tsunami hit, caught fire last night.