The Bougainville counterattack (also known as the "Second Battle of Torokina") was an unsuccessful Japanese offensive against the Allied base at Empress Augusta Bay, Bougainville Island during the Pacific War. Concentrated against the US-held perimeter around Torokina, the Japanese attack began on 8 March 1944 after months of preparations, but was repulsed by United States Army forces in fighting which lasted until the 25th of the month. The attack was hampered by inaccurate intelligence and poor planning and was ultimately defeated by the well-prepared Allied defenders who greatly outnumbered the Japanese force. The Japanese suffered severe casualties, while Allied losses were light.