DANGEROUS levels of radiation leaking from a crippled nuclear plant forced Japan to order 140,000 people to seal themselves indoors yesterday after an explosion and a fire escalated the crisis spawned by a deadly tsunami.

Tropical storm Chataan killed four people today as it struck along the coastline of northern Japan, burying an elderly man in a landslide and sweeping away a woman and her house in a flash flood.

A tropical storm has hit central Japan forcing thousands of people to be evacuated in two northeastern cities.