Three Chinese People's Liberation Army (PLA) Navy vessels, including two missile frigates, have for the first time docked in Bangladesh, sailing through the Bay of Bengal this week for a five-day visit.

The PLA Navy's 21st fleet, comprising the guided-missile frigates Liuzhou and Sanya, and a comprehensive supply ship Qinghaihu, arrived in Chittagong port on Wednesday.

This was the first time that a Chinese navy escort fleet had visited Bangladesh, the Communist Party's official People's Daily said on Thursday.

The three ships were welcomed by a Bangladesh Navy ship as they entered the Bay of Bengal, followed by a grand welcoming ceremony at a port that China has helped finance, underlining Beijing's increasing presence in the Indian Ocean. China has also helped build ports in Sri Lanka.

The first PLA Navy visit to the country comes months after China launched a frigate built specially for the Bangladesh Navy, which last year purchased two guided-missile frigates from China, reflecting deepening military ties.

The Bangladesh Assistant Chief of Naval Staff Rear Admiral Syed Abu Mansur Arshadul Abedin told official Chinese media at last year's launch in the city of Wuhan along the Yangtze river that the frigate will be their navy's most advanced, weighing 1,300 tons, built for 80 crew and equipped with two 76 mm and 30 mm guns as well as missiles.

The frigate can "detect, identify and destroy surface and aerial targets and can also carry out maritime monitoring and patrols", Cai Libin, deputy general manager of the Wuchang shipbuilding company that constructed the frigate, told the official Xinhua news agency.

The PLA Navy has in recent years taken increasing interest in the Indian Ocean Region, analysts say. Besides China's involvement in a number of port projects, which Beijing maintains are purely commercial ventures, the PLA Navy has undertaken an increasing number of anti-piracy escort missions in the Indian Ocean and Gulf of Aden. The Indian Ocean, Chinese experts say, is crucial for China as much of its energy imports pass through its sea lines.

In November, China said it was in discussion with Djibouti to open what would be the PLA Navy's first overseas military logistics facility, located near the Gulf of Aden, in a strategic location that will give the PLA Navy access to the Indian Ocean.

The Chinese Foreign Ministry, which maintained the facility would be more a 'logistics centre' than a full-fledged base, said it would be aimed at "helping Chinese vessels better carry out UN operations like escort missions and humanitarian assistance".