I have seen many such claims from pro-YPG users on Twitter... 350 000 civilians in Afrin city to 1 000 000 civilians in Afrin region about to get massacred by the fascist Turks and their jihadist allies and etc. Once I asked where are those hundreds of thousands of people living in a city whose pre- war population was around 40 000 with no refugee camps in sight and a population growth of 800% in a few years that must be very easily visible and hard to handle in a city with a few thousand buildings.
I don't expect them YPG rats to be civil engineers and urban planners but those are obvious lies that everyone with at least half of a brain won't believe so easily.