A bone anchoring device includes an anchoring element having a shank to be anchored in a bone or a vertebra, a receiving part connected to the shank the receiving part having a first end opposite to the shank and a second end facing the shank, a longitudinal axis passing through the two ends, a bore coaxial with the longitudinal axis extending from the first end through at least a portion of the receiving part and a substantially U-shaped recess for receiving a rod The U-shaped recess forms two free legs extending in the direction of the first end, the legs are provided with an internal thread. A locking device for securing the rod in the receiving part is provided which includes an external thread cooperating with the internal thread. An engagement structure is provided at the circumference of least a part of the outer surface projecting above the first end of the receiving part, the structure being engageable with a tool in a form-fit manner and wherein a maximum outer diameter of said first locking member in the region of said structure is larger than the inner diameter of the internal thread of the receiving part.
