If you look carefully, the video is taken with a medium-quality thermal camera (FLIR). The personnel moving on the ground could have been moving single file for a number of reasons, such as through a breach in a minefield or similar obstacle, to avoid IEDs, or because they were trying to infiltrate to a specific point and then assault a fixed position.

They don't appear to be refugees because they seem to be of a uniform height, and all seem to be moving at the same rate of speed. That's not something you'd see with women, children, and old men shuffling along.

As for the ordnance? Anybody's guess. Could be simple HE from mortars or artillery. If it was, government forces had that pre-registered target laid in very well.