Washington, Rabi'I 17, 1438, Dec 16, 2016, SPA -- China has seized a US unmanned underwater vehicle in the South China Sea, the Pentagon said Friday. The US Defence Department is demanding the return of the craft that it says was unlawfully seized Thursday while it was being recovered by a US Navy ship, spokesman Peter Cook said, accoridng to dpa. The drone known as an ocean glider was being used to collect military oceanographic data as part of routine operations near the Philippines when a Chinese Navy PRC DALANG III-Class ship intercepted it. The US Navy contacted the Chinese ship to ask for the return of the vessel, but was ignored, Cook said. Territorial disputes and navigation issues in the South China Sea have been a point of tension between China, its neighbours and the United States. New satellite images this week showed China has significantly strengthened its military capabilities on contested islands in the South China Sea. The incident also comes as Donald Trump prepares to become US president and as he has signaled a possible change in US policy toward China. -- SPA 23:44 LOCAL TIME 20:44 GMT www.spa.gov.sa/w292126