Malacca, Strait of (məläkˈə) [key], c.500 mi (800 km) long and from c.30 to 200 mi (50–320 km) wide, between Sumatra and the Malay Peninsula. Linking the Indian Ocean with the South China Sea, it is one of the world's most important sea passages. Chief ports include Belawan in Indonesia and Melaka and Penang in Malaysia; Singapore is at the southern end of the strait. The Strait of Malacca has been controlled by the Arabs, the Dutch, the Portuguese, and the British. In the mid-19th cent. it was a haven for pirates who menaced Dutch and British traders. Piracy remained a problem in the strait into the early 2000s.