Night of the Zombies (1981)

Investigators search for soldiers' missing bodies, and hear unbelievable rumors about zombies. Dismissing those rumors they set out to investigate. After two men are found dead, CIA special-agent Nick Monroe is sent to flush out what are suspected to be deserters from the old U.S. Army Chemical Corps unit. Nick's ruthless investigation uncovers a ghoulish plot of world domination, but first he must escape the horror that does not want to be known... yet!