When I first saw the footage of the explosion I figured it was a HE (high explosive) round fired from a distance. That means a cannon of some sort (tank, artillery, etc), far enough away that the cannon flash wasn't seen in the video.

They might have faked the satchel charge planting video out of concern about where the cannon is. If they put a fake story about it being a bomb, then no one is on edge about what the cannon will blow up next.