Chinese missile frigate "Xuzhou" (far back) escorts merchant vessels in the Aden Gulf on Aug. 1, 2009. The third Chinese naval flotilla for escorting mission started to protect merchant vessels from pirates in the Aden Gulf on Aug. 1. (Xinhua/Guo Gang)

Members of the Chinese naval special force board the helicopter based on China's missile frigate "Zhoushan", preparing to escort merchant vessels in the Aden Gulf on Aug. 1, 2009. (Xinhua/Guo Gang)

Members of the Chinese naval special force sit in the warship-based helicopter, preparing to escort merchant vessels in the Aden Gulf on Aug. 1, 2009. (Xinhua/Guo Gang)

Members of the Chinese naval special force land on merchant vessel "Yangdanghai" from the warship-based helicopter in the Aden Gulf on Aug. 1, 2009.(Xinhua/Guo Gang)