A locking assembly for securing a rod in a polyaxial bone anchoring device includes a first locking element having a first end, a second end, an outer surface with an external advancement structure, an inner wall, an internal advancement structure on the inner wall, and an engagement portion for a tool, and a second locking element having a first end configured to be oriented towards the first end of the first locking element, an opposite second end, an outer surface with an external advancement structure configured to cooperate with the internal advancement structure of the first locking element, and a portion at the second end having a width greater than a greatest width of the external advancement structure of the second locking element, wherein the second locking element is configured to move axially relative to the bone anchoring device at a speed different than the first locking element.