TOKYO, November 8 (Aalimi Nation) – A magnitude 5.7 earthquake struck central Japan in the early hours of Sunday, injuring more than 20 people in Aichi and Shizuoka prefectures, authorities said. No tsunami warning was issued.

The Japan Meteorological Agency said the quake occurred at about 1:04 am local time, with its epicentre in the western part of Shizuoka Prefecture at a depth of roughly 40 kilometres. The agency measured an upper 5 on Japan's seven-level seismic intensity scale in Chita City in Aichi Prefecture, the strongest shaking recorded in the event.

Japan earthquake: injuries and damage

Authorities in Aichi and Shizuoka said more than 20 people were hurt, with some of the injuries sustained while falling on stairs as residents hurried out of buildings. Local authorities in Shizuoka said at least three women sought emergency medical care, among them a woman in her nineties who injured her shoulder after falling from her bed. The injury figure is preliminary and could change as more reports arrive.

The shaking was felt across a wide area that included Aichi, Gifu and Yamanashi prefectures, home to Mount Fuji, as well as the historic cities of Kyoto and Nara. Tokyo, far from the epicentre, did not feel it. Shop windows shattered and glass was left on streets in affected areas, and a bookstore reported books thrown from its shelves. No deaths or structural collapses have been reported in the accounts available so far.

Transport and power plant checks

Some local train services were suspended after the quake. Tokaido Shinkansen bullet trains were delayed between Shizuoka and Gifu-Hashima stations while safety inspections were carried out.

Chubu Electric Power, which operates the Hamaoka Nuclear Power Plant in Shizuoka, said it had detected no disruption or abnormality at the facility. The central government set up a liaison office to coordinate its response to the quake.

Warning of further tremors

The meteorological agency urged residents to stay alert for the possibility of further strong shaking over the coming week, particularly during the next two to three days. Agency official Ayataka Ebita said: "Please be on the lookout for mudslides, falling rocks and the possible effects from rainfall."

Ebita also said that no apparent change had been detected so far in the Nankai Trough, the undersea trench where scientists say a major earthquake could eventually occur. The agency has described the likelihood of a link between Sunday's quake and a possible Nankai Trough megaquake as low.

Background

Japan lies along several tectonic plate boundaries and experiences a large share of the world's earthquakes. The Nankai Trough, which runs off the country's Pacific coast, is closely monitored because of the risk it poses to coastal regions, and the agency's statement on Sunday was aimed at addressing public concern about any link.

Authorities are expected to release updated injury counts and damage assessments once local inspections are complete.