Two armored vehicles were up front, followed by a large pack of monsters.
They seemed human in form, but the reason the Li brothers could swiftly determine it was an enemy attack was because normal humans couldn't possibly run that fast.
Besides, they were now more than two hundred kilometers away from Djibouti, and no one could run that far, chasing armored vehicles all the way from Djibouti to here.
So, it had to be monsters, and the likelihood of zombies was slim because, although zombies have strong short-distance bursts of speed, this kind of long-distance trek tested endurance, something zombies don't possess.
The two armored vehicles up front had spotted their convoy, but instead of heading directly towards them, they attempted to bypass on one side, so as to lead the pursuing monsters away as well.