The magnitude 6.1 earthquake struck the city of Osaka and the surrounding area about 8 a.m. (2300 GMT Sunday).
VIDEO: What to pack in your earthquake emergency kit
What to pack in your earthquake emergency kit
The Fire and Disaster Management Agency said the number of the injured had risen to 91 about three and a half hours later. Municipal authorities have confirmed three deaths in Osaka and a nearby city, a 9-year-old girl and two men in their 80s.
The quake set off building fires, toppled concrete walls and cracked roads and water pipes. Dozens of flights in and out of Osaka were grounded and train service was suspended across a wide area.
Click here for more stories and videos related to earthquakes.