A door blocking device including a retaining member movable, along a given path, between a work position and a rest position, in which it respectively cooperates with and does not cooperate with a coupling member of the door when the door is in a closed position; and controlled-actuation means for controlled actuation of the retaining member, and which include elastic means for pushing the retaining member into the rest position; means for moving the retaining member into the work position in opposition to the elastic means; a rotary member having at least one radially projecting peripheral lobe; and an electrically controlled actuator for moving the rotary member selectively between a first angular position, in which the at least one lobe does not interfere with the given path (T), thus allowing the retaining member to move between the work position and the rest position, and a second angular position, in which the lobe interferes with the given path to lock the retaining member in the work position in opposition to the elastic means.