Outside the fence...
Blast near US Embassy in Beijing reports (PHOTO, VIDEO)
https://www.rt.com/news/434284-china-blast-us-embassy/
Earlier in the day, a lady who was splashing gas on herself was arrested before she could self-immolate.
You've heard of the Keystone Cops? Well, this sounds like the Keystone Bombers.
There are some wacky Mooslims in northwestern China regions who are not beyond using violence at real or imagined enemies of their faith.
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A few years back some Mooslims from the same region set off a backpack bomb at a temple site in downtown Bangkok, tragically killing about 15 and injuring dozens more. The Mooslim group with connections in Northwestern China and Turkey was blamed for the explosion and a couple of the dozen or so considered/blamed for the attack are in the very slow process of being prosecuted for it.
It could be the same bunch or some similar wingnuts.