A missile frigate "Mianyang" (R) and a missile destroyer "Harbin" wait at a port in Qingdao city, East China's Shandong province, Feb 16, 2013, preparing to depart for the Gulf of Aden and the sea off Somalia on escort missions. The flotilla, as the 14th batch of its kind to engage in escort missions, consists of a missile destroyer and a frigate as well as a supply ship which are all from the North Sea Fleet of the People's Liberation Army (PLA) Navy. [Photo/Xinhua]