R-Point (2004)

Korean director Su-chang Kong's horror film is set in Vietnam, where South Korean troops are fighting in support of the Americans. The base camp starts receiving radio messages from a patrol that went missing six months previously. The commander leads a unit out to investigate, ending up at R-point, an un-named area that has only known war and is devoid of human presence. But where humanity has fled, others may have come to fill the void, as the soldiers soon find out...