The two destroyers, Wuhan and Haikou, and the support ship Weishanhu have about 800 crew members, including 70 soldiers from the Chinese navy's special force, and are equipped with two helicopters, missiles, cannons and light weapons, Xinhua news agency said.
A Chinese Defense Ministry spokesman earlier said that their mission was to protect Chinese commercial shipping passing through the area. The Chinese Foreign Ministry said last week that seven of 1,265 of Chinese ships travelling through the area had come under attack, and one had been seized. Last week, the crew of a Chinese vessel fought off pirates with Molotov cocktails, bottles and a water cannon until international help arrived.
The task force will also escort ships carrying humanitarian loads for international organizations such as the UN World Food Program, and foreign ships on request. The fleet will not charge escort service or protection fees to ships, whether foreign or domestic.
The Chinese Defense Ministry said the mission has no plans to carry out land operations in Somalia. The mission could be withdrawn after three months, but the exact date will depend on the situation and relevant decisions by the UN Security Council.
This is China's first active naval operation outside the country's territorial waters since the 15th century. Chinese military ships left the country only to take part in joint operations or on goodwill visits to foreign ports.
The Chinese navy said it was also ready to work with other countries fighting pirates in the area.
Russia is one of 16 countries fighting piracy in the Gulf of Aden, where pirates have been increasingly active. Over 120 ships have been attacked so far this year, with around 40 vessels seized off the coast of Somalia, which has no functioning government to police its coastline. A total of 600 people are currently held hostage.
According to recent UN Security Council reports, some 2,000 pirates with 60 boats are currently active in the area. The pirates are estimated to have received up to $150 million in ransoms this year.
In October, Russia sent the Neustrashimy (Fearless) missile frigate from the Northern Fleet to East African waters to protect commercial shipping. The Neustrashimy will continue its mission until mid-January, when it will be replaced by the Pacific Fleet's destroyer the Admiral Vinogradov.
