content: A few have emerged: https://www.rt.com/news/313159-explosion-us-base-japan/ http://www.wsoctv.com/news/news/national/reports-explosions-near-military-facility-japan/nnPrQ/ http://www.ajc.com/news/news/national/reports-explosions-near-military-facility-japan/nnPrQ/ TL;DR: This appears to be an accidental fire in a munitions storage depot. That interpretation is subject to change as more information comes forward.