The source is certainly unreliable, a quick scan of the wiki sources give you that:

https://en.wikipedia.org/wiki/Iran_International

But does the number even matter? Whether its 4000 or 35000 the conduct has been unacceptable.

The real question is the solution, is reporting like this designed to be used as the backdrop to foreign intervention? How many people will be killed then?

"one death is a tragedy, a million is a statistic" - Not Stalin