A predictable pattern of events is unfolding in the Indian Ocean. India has announced a no-fly zone in the Bay of Bengal possibly for a missile test and almost simultaneously a Chinese missile tracking ship is poised to enter the Indian Ocean.

India has marked a stretch of water around 1,600km long stretching well beyond the Andaman Islands as a no-fly zone on April 3 and April 4.

The Yuan Wang 3 will be the third Chinese research ship to enter the Indian Ocean region in the last few weeks. The Xiang Yang Hong 01 was sailing close to India's eastern seaboard till a few days ago and was thought to be there to monitor an Indian missile launch.

At one point the Xiang Yang Hong 01 was barely 250 nautical miles from Vishakapatnam, India's key naval base on the east coast which is also the home base of its nuclear submarines. India conducted a test of its Agni-5 intercontinental ballistic missile on March 11. India had declared a 3,500km-long no fly zone before this test.

At the same time, a sister ship the Xiang Yang Hong 03 was said to be conducting oceanographic studies in international waters on India's west coast. The ship docked in Male in the Maldives.

The increased activity by Chinese survey, or spy ships, comes at a time when Sri Lanka may be forced to back down on its ban on such ships entering its ports through 2024. The Sri Lankans recently allowed a German ship to dock and that led to strong protests from the Chinese.

One possibility is that India could now hold a launch of the Agnibaan missile which was postponed in late February. The Agnibaan is scheduled to be one of India's first private sector launches which will take place in Sriharikota.

Meanwhile, the Yuan Wang 3 is approaching the Sunda Strait, which is an entry point to the Indian Ocean located between the Indonesian islands of Sumatra and Java.

The Yuan Wang 3 is described by China's Global Times as a 'space tracking ship' that monitors missile launches, both by the People's Liberation Army and foreign powers. It's a second-generation ship in the Yuan Wang class.

In December 2022, another Chinese surveillance ship, the Yuan Wang 5, had sailed into the Indian Ocean. An Indian missile test had been scheduled for between December 15-16 that year.

A month earlier to that another ship, the Yuan Wang 6 had also entered the Indian Ocean forcing India to cancel the scheduled test.