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https://www.koreatimes.co.kr/www/nation/2018/12/205_260807.html
"The vessel used fire-control radar not because of the P-1,
which was flying in Japan's air defense identification zone,
but because we tried to trace a North Korean warship
drifting near the inter-Korean sea border,"
a Navy official told Yonhap News Agency on condition of anonymity.