Japan PM says many still trapped under quake rubble

STORY: Survival rates drop off 72 hours after the quake, according to emergency responders. Kishida said a large number of people were believed to still be trapped beneath rubble and everything was being done to reach as many people as possible.

The number of Self Defence Force personnel working in the affected areas of central Japan's Ishikawa prefecture would more than double to 4,600 people over the course of January 4 to help with rescue and relief work, he said as survivors and media reports showed shortages of basic supplies including water.

Severed roads and the remote location of the worst-hit areas have complicated rescue efforts. Nearly 600 tremors have hit the Noto peninsula since the main quake.