Japan earthquake kills nearly 50 as damaged roads hinder search for survivors

• Thousands sent to help, struggling to reach worst hit areas.
  
• Rail services, ferries and flights into Noto peninsula suspended.
  
• Several world leaders including Joe Biden sent condolences.

More than 40 people were killed after a strong 7.6-magnitude earthquake struck Japan on New Year's Day with rescue teams on Tuesday struggling to reach remote locations where buildings had collapsed to look for possible survivors.

Monday's quake that struck in the middle of the afternoon, prompted residents in some coastal areas to flee to higher ground as tsunami waves hit Japan's west coast, sweeping some cars and houses into the sea.

Thousands of army, firefighters, and police officers have been sent to the devastated Noto peninsula in Ishikawa prefecture, but rescue efforts are hindered by damaged roads and difficulty in assessing the full extent of the aftermath.

Many rail services, ferries and flights into the area have been suspended. Noto airport has been closed due to damage to its runway, terminal and access roads, with 500 people stranded inside cars in its parking lot, according to Japan's public broadcaster NHK.

"The search and rescue of those impacted by the quake is a battle against time," Prime Minister Fumio Kishida said during an emergency disaster meeting on Tuesday, adding that helicopter surveys had discovered many fires and widespread damage to buildings and infrastructure.

Authorities in Ishikawa said they had confirmed 45 deaths from the earthquake so far, with half of those fatalities in hard-hit Wajima city near the quake's epicentre, with the death toll likely to rise, Reuters reported.

Firefighters have been battling blazes in several cities and trying to free more people trapped in collapsed buildings, Japan's fire and disaster management agency said.

Over 140 tremors have been detected since the quake first hit on Monday, according to the Japan Meteorological Agency which warned more strong shocks could hit in the coming days.

A local said nearly 20 people were in her house for a New Year celebration when the quake struck but miraculously all emerged uninjured.

"It all happened in the blink of an eye," she said.

Several world leaders sent condolence messages with United States President Joe Biden saying in a statement that Washington was ready to provide any necessary help to Japan.

"Our thoughts are with the Japanese people during this difficult time," he said.

The Japanese government evacuated around 100,000 people on Monday night, sending them to sports halls and school gymnasiums.

Many returned to their homes on Tuesday, but 33,000 households remained without power in Ishikawa prefecture after temperatures dropped below freezing.

Most areas in the northern Noto peninsula also lack water supply, NHK reported.

Additional input from Reuters