Police and firefighters on Friday began investigating the fire that destroyed Okinawa's Shuri Castle the previous day.
The fire, which started at around 2:30 a.m. Thursday, engulfed seven wooden buildings that occupied more than 4,000 sq. meters of a hill overlooking the prefectural capital of Naha. It was extinguished at around 1:30 p.m. There were no reports of injuries.
As around 100 local officials entered the site in the morning, smoke was still rising from the remnants of the castle's Seiden main hall, where the authorities suspect the fire started.