evidence: Matsu Island, small island under the jurisdiction of Taiwan in the East China Sea, lying off the Min River estuary of mainland China and about 130 miles (210 km) northwest of Chi-lung (Keelung), Taiwan. Matsu is the main island of a group of 19, the Matsu Islands, which constitute Lien-kiang (Lienchiang) hsien (county). The island has a hilly terrain of igneous rock and a monsoonal subtropical climate. Fishing is the main economic activity. The islanders also raise vegetables, grain, hogs, and chickens, aided by an extensive system of reservoirs and wells. Once part of the mainland’s Fujian province, Matsu and the other islands were occupied by the Nationalist Chinese when they were driven from the mainland to Taiwan in 1949. Thereafter, Matsu and Quemoy Island to the south were central to the ongoing tension between Taiwan and the mainland, and both subsequently came under periodic artillery bombardment by communist forces on the mainland. One such incident, in 1958, provoked an international diplomatic crisis when the communists combined a heavy bombardment with the demand that the Nationalists surrender. The standoff was diffused only after the United States had interposed the 7th Fleet between the mainland and Taiwan. The island group remained under military rule until 1992. Area Matsu Island, 4 square miles (10 square km). Pop. (2003 est.) county, 8,732.