A magnitude 5.7 earthquake struck central Japan early on Sunday, injuring at least 22 people, shattering shop windows and forcing bullet trains to slow while railway operators checked for damage. No deaths have been reported.

The quake hit at 1:04am local time on Sunday, 8 November, centred in western Shizuoka Prefecture at a depth of about 40 kilometres, according to the Japan Meteorological Agency. The US Geological Survey measured the tremor slightly lower, at magnitude 5.5.

Where and when it struck

The strongest shaking was recorded in neighbouring Aichi Prefecture, where the city of Chita registered upper 5 on Japan's seven-level seismic intensity scale. The agency said it was the first time an earthquake of upper 5 or stronger had struck Aichi since March 1997.

Shaking was felt across a wide area, including the city of Hamamatsu in Shizuoka, the historic capitals of Kyoto and Nara, and the prefectures of Gifu and Yamanashi, where Mount Fuji is located.

Injuries and damage

At least 22 people were injured, according to local media reports carried by the Associated Press. The Fire and Disaster Management Agency said 19 people were injured in Aichi Prefecture and three in Shizuoka Prefecture. The figures were preliminary and could change as local authorities completed their assessments.

Some of those hurt were injured falling on stairs as they tried to leave buildings during the shaking. Shop windows shattered and goods fell from shelves, while residents fled buildings in the dark. Railway operators slowed Shinkansen bullet trains to check tracks and structures, disrupting services across the affected region.

No tsunami warning

No tsunami warning was issued after the quake, because the epicentre was inland and about 40 kilometres below the surface. No abnormalities were detected at the Hamaoka Nuclear Power Plant in Shizuoka Prefecture, its operator, Chubu Electric Power, said.

Aftershock warning for the week ahead

The Japan Meteorological Agency warned people in the affected areas to be ready for further strong earthquakes over the coming week, especially in the next two to three days. Smaller aftershocks followed the main tremor.

Ayataka Ebita, an official of the agency, told reporters that people should also watch for secondary hazards, including mudslides and falling rocks, after the shaking.

Checks on Filipino workers

On Tuesday, the Philippines' Department of Migrant Workers said its offices in Tokyo were coordinating with the Philippine Embassy and Japanese authorities to check on the safety of Filipino workers in central Japan. The department said no Filipino casualties or injuries had been reported, and that monitoring was continuing.

The quake struck in a region Japan has long watched closely, because it sits within the broader area considered in planning for a much larger earthquake along the Pacific coast. Sunday's tremor was far smaller than that feared event, but it was a reminder of the country's exposure to seismic risk.