On 9 February 1945, a force of Allied Bristol Beaufighter aircraft suffered heavy casualties during an unsuccessful attack on the German destroyer Z33 and its escorting vessels; the operation was labelled "Black Friday" by the surviving Allied aircrew. The German ships were sheltering in a strong defensive position in Førde Fjord, Norway, forcing the Allied aircraft to attack through heavy anti-aircraft fire. The Beaufighters and their escort of Mustang IIIs (North American P-51 Mustang) fighters from the RAF's No. 65 Squadron were also intercepted by twelve German Focke-Wulf Fw 190 fighters of the Luftwaffe fighter wing Jagdgeschwader 5. In the resulting attack, the Allies damaged at least two of the German ships for the loss of seven Beaufighters shot down by flak guns. Another two Beaufighters and one Mustang were shot down by the Fw 190s.