The death toll from a powerful earthquake in Japan that struck the country’s west coast on New Year’s Day rose to 73 on Thursday, as the search for survivors under collapsed buildings continued and tens of thousands of evacuees awaited aid.

All the deaths from the magnitude 7.6 quake have been reported in Ishikawa prefecture where the hardest hit Noto peninsula is located. More than 33,000 people have evacuated their homes and about 100,000 houses have no water supply, according to the local government.

Thousands of rescuers raced against the clock to free many more people still trapped under rubble amid freezing temperatures and heavy rain, but severed roads and the remote location of the hardest-hit areas have complicated their efforts.

The full extent of damage and casualties remains unclear three days after the quake, which is already the deadliest in Japan since at least 2016. Nearly 600 tremors continue to hit the peninsula, raising fears of landslides and further damage to the infrastructure.

Japan’s government opened a sea route to deliver aid and some larger trucks were now able to reach some of the more remote areas, Prime Minister Fumio Kishida told a Wednesday press conference following a national disaster response meeting.