In this article we analyze the structure of
-categories
of symmetric projective bimodules over a finite dimensional algebra with respect to the
action of a finite abelian group. We determine under which condition the resulting
-category
is fiat (in the sense of Mazorchuk and Miemietz (2011)) and classify simple transitive
-representations
of this
-category
(under some mild technical assumption). We also study several classes of examples in
detail.