Besides the two fighter squadrons, two Polish bomber squadrons were formed: 300 sqn  "Ziemi Mazowieckiej" and 301 sqn "Ziemi Pomorskiej". Both units were equipped with  Fairey Battle Mk. I bombers. They entered the combat on the night of September 14, 1940 during the so-called Battle of Barges. During the Battle of Britain, the Polish aircraft from 300 and 301 squadrons made night bombing of the German landing ships based in Boulogne, Calaise and Oostende.