Tokyo quake threat

An estimated 13,000 people would die and 800,000 homes could be destroyed if a severe earthquake struck directly underneath Japan's densely populated capital.

The Cabinet Office's disaster management and prevention panel predicted the worst case scenario after studying 18 types of magnitude 6.9 earthquakes and the potential damage that could be inflicted if Tokyo was hit.

Many houses would be destroyed by rapidly spreading fires, the panel said.

A quake with an estimated magnitude of 8.3 hit Tokyo in 1923, killing 142,000 people. Powerful quakes also hit in 1703, 1782, 1812 and 1855.

Japan is one of the world's most earthquake-prone countries as it sits atop four tectonic plates.