It seems Lebanon did not appreciate Kuwait coming to its stadium and winning 6-0 in a friendly, because starting a battle royale that prompts the military to fire warning shots into the air (about 2:00 into the video) isn't how friendlies usually end.
The fighting carries on throughout the video until the military police eventually usher the Kuwait team into the tunnel. At least one player is left bleeding from the head. An important lesson is learned in all this, though. That international teams violently attacking each other won't stop what they're doing just because the military fires a few piddly warning shots.