Pakistani P-3C Orion aircraft are seen during the AMAN-13 exercise in the Arabian Sea, March 8, 2013. Naval ships from 14 countries, including China, the United States, Britain and Pakistan, joined a five-day naval drill in the Arabian Sea from March 4, involving 24 ships, 25 helicopters, and special forces. (Xinhua/Rao Rao)

Naval ships from various countries are seen during the AMAN-13 exercise in the Arabian Sea, March 7, 2013. Naval ships from 14 countries, including China, the United States, Britain and Pakistan, joined a five-day naval drill in the Arabian Sea from March 4, involving 24 ships, 25 helicopters, and special forces. (Xinhua/Rao Rao)

Helicopters fly over a naval ship during the AMAN-13 exercise in the Arabian Sea, March 8, 2013. Naval ships from 14 countries, including China, the United States, Britain and Pakistan, joined a five-day naval drill in the Arabian Sea from March 4, involving 24 ships, 25 helicopters, and special forces. (Xinhua/Rao Rao)

Chinese Navy's missile destroyer "Harbin" fires during the AMAN-13 exercise in the Arabian Sea, March 8, 2013. Naval ships from 14 countries, including China, the United States, Britain and Pakistan, joined a five-day naval drill in the Arabian Sea from March 4, involving 24 ships, 25 helicopters, and special forces. (Xinhua/Rao Rao)

Pakistani powerboats are seen during the AMAN-13 exercise in the Arabian Sea, March 7, 2013. Naval ships from 14 countries, including China, the United States, Britain and Pakistan, joined a five-day naval drill in the Arabian Sea from March 4, involving 24 ships, 25 helicopters, and special forces. (Xinhua/Rao Rao)