At least 48 people were killed in the powerful earthquake that struck western Japan on Monday, the authorities said a day after the disaster, as they continued to comb through the rubble of collapsed and burned buildings.

The dead included 19 in Wajima, a city in Ishikawa Prefecture, the coastal epicenter of the earthquake, which triggered tsunami warnings, extensive evacuations and widespread power outages after it hit around 4:10 p.m. on New Year’s Day.

A large fire broke out in Wajima after the quake, which registered 7.6 on the Japanese seismic intensity scale. Some died after being trapped in rubble from destroyed buildings.

The tsunami warnings were lifted on Tuesday morning, and the quake did not produce waves as high as initially feared. The police, firefighters and members of the country’s Self-Defense Forces were still assessing the damage, which included buckled roads along with charred houses and commercial facilities.

About 33,000 homes in Ishikawa and neighboring Niigata Prefecture were without power on Tuesday morning, said Yoshimasa Hayashi, chief cabinet secretary. Close to 20,000 homes across four prefectures lacked running water. Mr. Hayashi said that 57,360 people had fled their homes and gone to nearly 1,000 different evacuation facilities across the affected prefectures.

He said officials continued to search for people buried under rubble after 120 such incidents were reported to local police or fire departments, raising the possibility of a higher death toll. Mr. Hayashi said that nuclear power plants in the affected prefectures continued to report no abnormalities.

Officials warned residents in the affected areas to brace for further aftershocks, landslides or new tsunami warnings. Speaking to reporters at a briefing on Tuesday morning, Noriko Kamaya of the Japan Meteorological Agency said there was a 10 to 20 percent chance that an earthquake of equivalent intensity could occur in the next week. She urged residents to exercise caution during sea-based activities such as fishing.

Prime Minister Fumio Kishida told reporters on Tuesday that teams were working to clear roads blocked by landslides or damaged buildings. He also said that retailers were supplying water, food, blankets, portable toilets and more to those housed in evacuation centers.

Miharu Nishiyama contributed reporting from Tokyo.