[kach22i]

Russian diplomats appear to be burning documents in DC and San Francisco
https://www.google.com/amp/s/twitchy.com/gregp-3534/2017/09/01/russian-diplomats-appear-to-be-burning-documents-in-dc-and-san-francisco/amp/

According to reports, the Russians are saying the FBI will search the compounds tomorrow which would explain the fires:

I would think the US embassy/consulate did the same when bugging out and reducing staff. Then again, reports indicate strong motive.

https://en.m.wikipedia.org/wiki/Burn_bag

A burn bag is the informal name given to a container (usually a paper bag or some other waste receptacle) that holds sensitive or classified documents which are to be destroyed by fire or pulping after a certain period of time. The most common usage of burn bags is by government institutions, in the destruction of classified materials.