A circuit breaker includes: first and second contacts moveable relative to each other along an axis of the circuit breaker between an open and closed configuration and defining an arcing region in which an arc is formed during current breaking operation; a nozzle directing a flow of quenching gas onto the arcing region during current breaking operation, a diffusor downstream of the nozzle for further transporting the quenching gas within the arcing region and/or downstream of the arcing region, and a mechanical swirling device arranged downstream of the nozzle and at least partially in the diffusor for imparting a swirl onto the quenching gas flowing along the diffusor, the mechanical swirling device having an axial overlap with the second contact in the open configuration of the circuit breaker.