Rear Admiral Xia Kewei (2nd L), political commissar of the 11th Chinese naval escort taskforce, shake hands with Kiril Yordanov (1st R), mayor of Varna, during their meeting at Bulgarian Black Sea port of Varna on Aug. 6, 2012. The frigate "Yantai", one of the 11th group of Chinese navy escort ships for an escort mission on the Gulf of Aden and Somali waters, arrived here on Sunday to make a five-day goodwill visit. It is the first visit of Chinese navy ship in Bulgaria ever. (Xinhua/Zhou Lei)

Kiril Yordanov (2nd L), mayor of Varna, meets with Rear Admiral Xia Kewei (3rd R), political commissar of the 11th Chinese naval escort taskforce, at Bulgarian Black Sea port of Varna on Aug. 6, 2012. The frigate "Yantai", one of the 11th group of Chinese navy escort ships for an escort mission on the Gulf of Aden and Somali waters, arrived here on Sunday to make a five-day goodwill visit. It is the first visit of Chinese navy ship in Bulgaria ever. (Xinhua/Zhou Lei)

Bulgarian navy officers look at the helicopter on the deck of the frigate "Yantai" at Bulgarian Black Sea port of Varna on Aug. 6, 2012. The frigate "Yantai", one of the 11th group of Chinese navy escort ships for an escort mission on the Gulf of Aden and Somali waters, arrived here on Sunday to make a five-day goodwill visit. It is the first visit of Chinese navy ship in Bulgaria ever. (Xinhua/Zhou Lei)

Bulgarian navy officers visit the frigate "Yantai" at Bulgarian Black Sea port of Varna on Aug. 6, 2012. The frigate "Yantai", one of the 11th group of Chinese navy escort ships for an escort mission on the Gulf of Aden and Somali waters, arrived here on Sunday to make a five-day goodwill visit. It is the first visit of Chinese navy ship in Bulgaria ever. (Xinhua/Zhou Lei)

Bulgarian navy officers visit the frigate "Yantai" at Bulgarian Black Sea port of Varna on Aug. 6, 2012. The frigate "Yantai", one of the 11th group of Chinese navy escort ships for an escort mission on the Gulf of Aden and Somali waters, arrived here on Sunday to make a five-day goodwill visit. It is the first visit of Chinese navy ship in Bulgaria ever. (Xinhua/Zhou Lei)

Bulgarian navy officers look at the helicopter on the deck of the frigate "Yantai" at Bulgarian Black Sea port of Varna on Aug. 6, 2012. The frigate "Yantai", one of the 11th group of Chinese navy escort ships for an escort mission on the Gulf of Aden and Somali waters, arrived here on Sunday to make a five-day goodwill visit. It is the first visit of Chinese navy ship in Bulgaria ever.(Xinhua/Zhou Lei)

Bulgarian navy officers leave after they visited the frigate "Yantai" at Bulgarian Black Sea port of Varna on Aug. 6, 2012. The frigate "Yantai", one of the 11th group of Chinese navy escort ships for an escort mission on the Gulf of Aden and Somali waters, arrived here on Sunday to make a five-day goodwill visit. It is the first visit of Chinese navy ship in Bulgaria ever. (Xinhua/Zhou Lei)

A Bulgarian navy officer looks at the helicopter on the deck of the frigate "Yantai" of the 11th Chinese naval escort flotilla in the Bulgarian Black Sea port of Varna on Aug. 6, 2012. The frigate "Yantai" arrived here on Sunday to make a five-day goodwill visit. It is the first visit of Chinese navy ship in Bulgaria ever. (Xinhua/Zhou Lei)