SUZU, Ishikawa Prefecture--Rescue workers and canine units urgently sifted through rubble Wednesday ahead of predicted freezing cold and heavy rain in what the prime minister called a race against time after powerful earthquakes in western Japan killed 62 people. Dozens are believed trapped under collapsed buildings.

Ishikawa prefecture and nearby areas were rattled by a 4.9 magnitude aftershock early Wednesday — one of dozens of aftershocks that have followed Monday's shallow magnitude 7.6 temblor with an epicenter at Noto, Ishikawa prefecture, about 300 kilometers (185 miles) from Tokyo on the opposite coast. The shaking set off tsunami warnings, followed by waves measuring more than 1 meter (3 feet) in some places.

The first 72 hours are especially critical, experts say, because the prospects for survival greatly diminish after three days.

“More than 40 hours have passed. This is a race against time, and I feel that we are at a critical moment,” Prime Minister Fumio Kishida told reporters. “We have received reports many people are still waiting for rescue under collapsed buildings.”

Noto’s narrow peninsula landscape has added to the challenges in reaching some communities. Water, power and cell phone service were still down in some areas.

“Hardly any of the homes are standing. They are either partially or totally destroyed,” said Masuhiro Izumiya, the mayor of neighboring Suzu city, which suffered heavy damage.

Relief officials handed out water, blankets, food and other supplies. Search dogs joined military personnel and firefighters trying to find and rescue dozens of people who are thought to be trapped, although the exact number is unclear.

Weather forecasts warned of heavy rainfall in Ishikawa, leading to worries about landslides and further damage to half-crumbled homes. Temperatures were expected to drop to around 4 degrees Celsius (39 degrees Fahrenheit) overnight.

Of the deaths, 29 were counted in Wajima city, while 22 people died in Suzu, according to Ishikawa Prefectural authorities. Eleven deaths were reported scattered among other nearby towns, and two additional deaths were still awaiting official confirmation in Wajima, meaning the overall toll would likely grow to 64 people. Dozens of people have been seriously injured, including in nearby prefectures.

Ishikawa Governor Hiroshi Hase encouraged everyone to use masks, antiseptic and soap to guard against the spread of infectious diseases as evacuees sheltered together. Ensuring adequate water supplies and bathroom services for those who were displaced is a priority, he said.

People on the coastline were already picking up the pieces, like Noto resident Kazuyuki Iwaike, who was deep in thought as he cleaned up his home. It was by sheer chance he had avoided death. He was not home when the tsunami that followed the earthquakes struck.

“I always thought it was someone else’s problem, thinking there is no way a tsunami would come,” he said.

Officials warned that things were unpredictable and it was possible that even bigger quakes could hit.

In the aftermath of the quakes and tsunami, boats lay overturned in water, roads were blocked by mounds of dirt, and shovels scooped scattered pillars and walls from flattened homes. A large fire turned an entire section of Wajima city into ashes.

As a quake-prone nation with crisscrossing fault lines and many volcanoes, Japan has had its share of disasters, including a quake, tsunami and nuclear disaster in northeastern Japan in 2011.

Several nuclear plants in the region raised concern, although no major problems or rise in radiation levels have been reported. Shika nuclear plant in Ishikawa suffered partial electricity failure, but backup power kicked in, ensuring the critical cooling process continued.

Japan is an organized, conformist and relatively crime-free society, where warnings are systematically relayed as a public service. Disaster experts say that’s helping save lives.

The Japan Meteorological Agency lifted tsunami warnings Tuesday.

Australian Prime Minister Anthony Albanese joined United States President Joe Biden and other world leaders in expressing sympathy for the Japanese.

“Our hearts go out to our friends in Japan,” Albanese said. “We will provide, and have offered, whatever support is requested by our friends in Japan.”