Japan toll tops 18,000

The number of people confirmed as dead or listed as missing by Japan's national police agency has topped 18,000 - eight days after the massive earthquake and tsunami struck.

There were fears of a far higher death toll from the disaster that wiped out vast residential areas along the Pacific coast of northern Honshu island.

The national police agency said 7197 people had been confirmed dead and 10,905 officially listed as missing - a total of 18,102 - as of 9am on Saturday (1100 AEDT) as a result of the March 11 catastrophe.

Hopes of finding many more survivors amid the rubble have diminished amid a cold snap that has hit Japan's northeast, covering much of the disaster area in snow earlier this week.

The death toll has surpassed that of the 7.2-magnitude quake that struck the western Japanese port city of Kobe in 1995, killing 6434 people.

The March 11 quake is now Japan's deadliest natural disaster since the 1923 Great Kanto Earthquake, which killed more than 142,000 people.

The latest police figures for people missing do not include local reports from along the tsunami-hit coast of vast numbers of people unaccounted for.

The mayor of the coastal town of Ishinomaki in Miyagi prefecture said on Wednesday that the number of missing there was likely to hit 10,000, Kyodo News reported.

On Saturday, public broadcaster NHK said that around 10,000 people were unaccounted for in the port town of Minamisanriku in the same prefecture.