Saw two faceless aliens in the woods. Was witnessed by my father and his brother

This is a story my father and his brother have told me about the time they belive they saw two alien beings. 
My fater and his brother were walking through the woods along the rail road tracks.  They saw two short beings wearing long black over coats and large brimmed hats.
The two beings faced them and My father and his brother saw that they had no face.  It was completly blank and white.
My father and his brother took off running away from the two beings. 
Im not sure weather this story is true.  My father assures me it is and I can only take his word for it.
Date of alleged incident is unknown.  PD