Shizuoka, Japan — Magnitude 5.7 Earthquake Injures 20-Plus

A magnitude 5.7 earthquake struck western Shizuoka prefecture in central Japan at 1:04 a.m. local time Sunday, injuring more than 20 people and shattering storefront windows, according to the Japan Meteorological Agency, cited by Al Jazeera.

How strong was the quake and where did it hit?

The Japan Meteorological Agency recorded the quake at a depth of about 40 kilometers, or 25 miles, with the epicenter in western Shizuoka prefecture, Al Jazeera reported. The agency measured the magnitude at 5.7. The quake struck at 1:04 a.m. local time Sunday, which was 16:00 GMT Saturday.

How many people were hurt?

More than 20 people were injured across Aichi and Shizuoka prefectures, Kyodo News reported, citing local authorities. Some of the injured fell on stairs while trying to flee buildings, the Associated Press reported. Japanese television footage showed shattered shop windows and glass scattered across streets, along with a bookstore where shelves had emptied onto the floor.

How far did the shaking spread?

The tremor was felt across a wide area that included the city of Hamamatsu in Shizuoka prefecture, the ancient capitals of Kyoto and Nara, Yamanashi prefecture near Mount Fuji, and Gifu prefecture, according to Al Jazeera. Tokyo, which sits farther from the epicenter, did not feel the quake. No tsunami warning was issued, Kyodo reported.

Why are officials warning about aftershocks?

The meteorological agency told residents to prepare for the possibility of strong aftershocks over the next week, with the highest risk in the following two to three days. "Please be on the lookout for mudslides, falling rocks and the possible effects from rainfall," agency official Ayataka Ebita told reporters, according to Al Jazeera.

Ebita said the agency had not detected any apparent change in the Nankai Trough, the undersea fault zone where two tectonic plates meet beneath parts of Japan and where scientists have long warned a megaquake could eventually occur.

What transportation disruptions followed the quake?

Some local train services were suspended after the quake. Shinkansen bullet trains ran at reduced speeds in affected areas as a precaution, and JR Central reported delays on the Tokaido Shinkansen line, which links Tokyo and Osaka, between Shizuoka and Gifu-Hashima stations while crews conducted safety checks.

What to watch

• Whether the meteorological agency reports additional aftershocks in Shizuoka or Aichi prefectures over the coming days
• Any update on the Nankai Trough monitoring after Ebita's comments that no change had been detected
• Restoration timelines for local train service and Shinkansen speed restrictions on the Tokaido line
• Updated injury or damage figures from Kyodo News or Japanese local authorities as assessments continue

Authorities had not issued a tsunami warning as of the latest reporting, and Tokyo-area transit was not affected by the quake itself, according to Al Jazeera's account of local media and agency statements.