You, Snno, and the Captain walk a good distance before continuing forward on foot. The rumbles from the sweeper off in the distance were loud and you could hear screaming.

"There is screaming! Why?"

"Sweepers are the reason the land outside the city is almost devoid of life. They have a limited radius but anywhere they can reach they just kill everything. Some towns they are not authorized to engage. Anything humanoid is what it searches for. Primarily mutants. I don't think there is much you could probably do for them now."
The screaming continued and transformed into desperate cries for help or disgusting gurgling noises. The rumbles stopped.
*Rumble Rumble*
Mechanical noises are making it's way towards your group, you could hear each servo now as it drew nearer.