Chapter 375: Chapter 376 Retreat

After annihilating the enemy's troops in the air, the security center could finally focus on dealing with the corpse tides that were constantly attacking their position.

At a glance, the corpse tide was surging like a flood, roaring endlessly.

Their scarlet eyes sparkled with the crazy killing intent. What was more terrifying was that seeing that warriors at the front of the steel plant were so tenacious, the mutants behind the corpse tides finally could not bear it and joined the battle in person.

Although the firepower of the security center was fierce, ordinary bullets were useless to the mutant zombies.

Countless bullets hit the B-level mutants. But the sparks fly around without hurting them at all.

"Damn it! Our weapons are too small to penetrate the skin of these B-level mutants!"

"How's the preparation going at the base? We can't hold on any longer!"