At first, France recognized Chinese sovereignty of Spratly and Paracel islands, in exchange for Chinese recognition of Vietnam as a French territory. In 1932, a year after the Japanese formally invaded northeast China (Manchuria), France formally claimed both the Paracel and Spratly Islands. China and Japan both protested. In 1933, France seized the Paracels and Spratlys, announced their annexation, formally included them in French Indochina, and built a couple of weather stations on them, but did not disturb the numerous Chinese fishermen it found there. In 1938 Japan took the islands from France, garrisoned them, and built a submarine base at Itu Aba (now Taiping / 太平) Island. In 1941, the Japanese Empire made the Paracel and Spratly islands part of Taiwan, then under its rule.