Japanese rescuers scrambled to search for survivors Wednesday as authorities warned of landslides and heavy rain after a powerful earthquake that killed at least 55 people.

The 7.5 magnitude quake on January 1 that rattled Ishikawa prefecture on the main island of Honshu triggered tsunami waves more than a meter high, sparked a major fire, and tore apart roads.

The Noto Peninsula of the prefecture was most severely hit, with several hundred buildings ravaged by fire and houses flattened. 

The regional government announced late Tuesday that 55 people had been confirmed dead and 22 severely injured. 

But the toll was expected to climb as rescuers battle aftershocks and poor weather to comb through rubble.

More than 31,800 people were in shelters, they added. 

Prime Minister Fumio Kishida's government was due to hold a meeting of an emergency task force Wednesday morning to discuss responses.   

Kishida reiterated Tuesday night that "it's a race against time" given how many people may have been caught in the collapsed buildings, according to public broadcaster NHK.

The operation was given extra urgency as the Japan Meteorological Agency (JMA) issued a heavy rain warning for Noto.  

"Be on the lookout for landslides until the evening of Wednesday," the agency said.

In the coastal city of Suzu, mayor Masuhiro Izumiya said there were "almost no houses standing".

"About 90 percent of the houses (in the town) are completely or almost completely destroyed… the situation is really catastrophic," he said according to broadcaster TBS.

A woman at a shelter in the town of Shika told TV Asahi that she "hasn't been able to sleep" due to aftershocks. 

"I've been scared because we don't know when the next quake will hit," she said.