We firstly give a modification of the known Hermite-Hadamard type inequalities for the generalized k-fractional integral operators of a function with respect to another function. We secondly establish several Hermite-Hadamard type inequalities for the generalized k-fractional integral operators of a function with respect to another function. The results presented here, being very general, are pointed out to be specialized to yield some known results. Relevant connections of the various results presented here with those involving relatively simple fractional integral operators are also indicated.
Keywords: Gamma function; Hermite-Hadamard type inequalities; Riemann-Liouville fractional integrals; convex function; generalized k-fractional integral operators; k-gamma function.