It is shown that the correlations predicted by relativistic quantum field theory in locally normal states between projections in local von Neumann algebras A(V-1), A(V-2) associated with spacelike separated spacetime regions V-1, V-2 have a (Reichenbachian) common cause located in the union of the backward light cones of V-1 and V-2. Further comments on causality and independence in quantum field theory are made.