Horrible Dream On Explosion

I had a bad dream of being a sentry in probably a military camp.
My friend and I seem to be at the entrance of the camp.
Then there was a man walking a dog moving towards us.
My friend bent down to touch the dog.

Since I was about 2 meters behind my friend, I could see the man slowly walking away while my friend was preoccupied.

I mimic his movement and stepped away. I knew that something was wrong intuitively.

In about 30 seconds later, the dog exploded with its feet on the ground. My friend died and the man was nowhere to be seen.

I got stun for a moment then I just started running.

I know this dream is horrible and cruel but I cant make head or tail of it. What does it dream? Does it mean I should be cautious? Why such a dream?