These photographs and videos from Damascus and Aleppo claim to show the Syrian army using these truck mounted weapons, but the argument has been that these are clearly non-military vehicles, something only the Syrian opposition uses. While it's true the Syrian opposition mounts plenty of different weapons on trucks of various shapes and sizes, it's certainly not true that only the Syrian opposition uses non-military trucks in this way. The following video is from a missile test in the Summer of 2012, where a variety of missiles and rockets were launched from the 155th brigade base
As we can see in the video, there's clearly trucks with non-military colour schemes being used to launch large rockets or missiles
The same missile test was also broadcast on State TV, with images of the same vehicles
So it's pretty clear the claim that only the Syrian opposition uses trucks with non-military colours is an inaccurate statement. In fact, it's not that unusual, as these photos from an Iranian military parade shows (source)
More posted on the subject of the August 21st attacks can be found here, and other posts on chemical weapons and Syria, including extremely informative interviews with chemical weapon specialists, can be found here.
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