A Chinese nuclear submarine has completed an anti-piracy mission in the Gulf of Aden, demonstrating the navy's ability to operate in waters far from home. Military analysts said the deployment would cause unease among China's neighbours, but that Beijing would deploy more vessels to far-flung regions as it broadened its political and investment interests overseas. The military channel of state-run CCTV said on Sunday that the submarine patrolled the Gulf of Aden for more than two months, escorting two ships and a supply vessel, but had since returned to its base in Qingdao , Shandong province. The report did not specify the type of submarine, but some commentators say the footage suggests it was an updated version of a Type 091. CCTV interviewed Deputy Commander Yu Zhengqiang, who said the crew had to overcome many obstacles during the mission. "First, there were concerns about all the equipment and facilities, and second [we had to] deal with various challenges while sailing in totally unknown waters, which was complicated by military intelligence issues," he said. It is the first time state media has reported on the submarine's mission in the Gulf of Aden, though there has been speculation about it in overseas media. Analysts said the deployment was strategically significant, particularly because the region is seen as India's backyard. "Someone may argue that sending a submarine, especially a nuclear one, for an escort mission is not as efficient as [sending other] military vessels, but it is a good opportunity for the People's Liberation Army to test the reach of the vessel," said Ni Lexiong , a Shanghai-based military commentator. He said it was necessary for the PLA to undertake such missions to train personnel and test vessel performance. Antony Wong Dong, a Macau-based analyst, expected China would send more military vessels to the Gulf of Aden, especially as the country's engagement overseas would be boosted under the "One Belt, One Road" initiative. "China has to step up the protection of its interests abroad. Sending more military vessels [overseas] is essential to that aim," he said. Hsieh Tai-hsi, secretary general of the Taipei-based Society for Strategic Studies, said the deployment would concern both the United States and countries in the region, particularly India. He said India was already concerned about Pakistan's deal to buy eight Chinese submarines and China's involvement in port projects in South Asia. "But more importantly, through the mission, the PLA was able to cooperate with vessels from other countries, thereby allowing it to evaluate the capabilities and performances of the navies of these countries," he said. Hsieh said the deployment could help the PLA survey the underwater and hydrological conditions in the region, and help improve its battle strategies.