Crack propagation associated with two initially symmetrical cracks located at the interface between an inclusion and the surrounding matrix, subjected to remote traction, is studied by means of Griffith’s energy criterion within the framework of linear elastic fracture mechanics. Using Muskhelishvili’s method of complex potentials, we derive semi-analytical expressions of the stress intensity factor and energy release rate at the crack-tip. Based on these results, we discuss the mode of propagation of the cracks. Our analysis points at the possibility of a single-sided, rather than simultaneous, symmetric crack growth, even if both initial configuration and loading are symmetric.