Recent naval manoeuvres and land reclamation activities in the Spratly Islands have drawn attention to the risk of incidents at sea leading to growing tensions and even conflict in the South China Sea. On Tuesday 27 October 2015, the United States Navy sent its state-of-the-art guided-missile destroyer USS Lassen into waters within 12 nautical miles of Subi Reef, which China claims.Chinese naval vessels shadowed the USS Lassen until it left the waters around Subi Reef and Mischief Reef.