South Korea plans to deploy surveillance radars on a northwestern island to step up monitoring of North Korea following a series of defections on the west coast, a senior military official said Friday. The government has allocated 3.8 billion won (US$3.6 million) to place six short-range spy radars on Gyodong Island in the Yellow Sea within this year, the official said. The strategically important island is situated only 20 kilometers south of the 38th parallel that roughly divides the two Koreas and is 50 kilometers east of the sites of three major North Korean offshore provocations in the last decade. Though Marines are stationed on the island with a population of 5,000, some of its coastal areas are left open without a barbed-wire fence to allow for fishing by residents. "The radars would strengthen monitoring of North Korea from Gyodong Island, which has been considered a vulnerable region," the official said, asking for anonymity as he is not authorized to speak to media. The radar has a maximum detection range of 5 kilometers and is capable of monitoring moving objects at night as well as in bad weather. Last August, a NorthKorean man defected to South Korea via the island. In September 2012, another North Korean man sneaked into the island by holding on to a log that was swept away in flood waters spawned by typhoons.