Warning from Space (1956)

Synopsis
Translated into English, the title of this Japanese sci-fi endeavor is Unknown Satellite over Tokyo. The extraterrestrials on this occasion are weirdly shaped creatures with one eye in the middle of their bodies. The aliens take the form of human beings so that they can warn mankind of an imminent disaster: the earth is on a collision course with another planet. Once the creatures have conveyed their messages, a scientist races against time to create a bomb that will throw the other planet off its course. Alas, foreign spies, apparently unmindful that the destruction of earth will affect them too, steal the super-weapon, and the chase is on. ~ Hal Erickson, All Movie Guide