There seems to have been an explosion at the Aeon Mall Kumamoto in Kashima (near Kumamoto City). The image is from this live feed:

https://newsdig.tbs.co.jp/articles/-/2832102

-- Kirk

P.S. I still don't know the details about the explosion but after hearing that it occurred significantly after the quakes and that many people had already been evacuated I'm now hearing on NHK that people are trapped inside.