Burma is among 14 countries to take part in a joint naval exercise with India today in the Bay of Bengal, with the show of force likely to trigger concern in China that its close ally to the south is being drawn further into New Delhi’s orbit.

The five-day naval drill, known as the Milan exercise, is focused on joint efforts at combating piracy and terrorism in the strategically key waters off eastern India. Burma’s maritime territory also extends into the Bay of Bengal.

The Times of India said that of particular concern to regional countries is the stability of the Malacca Straits beneath Singapore, through which up to 60,000 vessels pass each year transporting cargo to and from Asia-Pacific economies. The Andaman and Nicobar Islands, around which this week’s exercises will take place, act as a gateway to the strait.

That choke-point is also a key route for Middle Eastern and African oil bound for China, which has already signalled concern about US warships that patrol beneath Singapore, and the potential for it to be cut off.

The sight of warships that belong to countries like India and Vietnam, whose relations with China are strained, carrying out joint drills in the Bay of Bengal is sure to unnerve Beijing, which has sought to develop an alternative to the Malacca Straits with the trans-Burma Shwe oil and gas pipelines.

China’s once unrestrained ability to tap Burma’s natural resources took a knock last October when Naypyidaw announced a decision to scrap the Myitsone Dam in Kachin state, which was financed by Beijing and whose output would have fed China’s southern Yunnan province.

The decision pointed to a growing unease within the Burmese government at its economic reliance on China, and Burma’s leaders will now seek to draw themselves away from Beijing through boosting economic and security cooperation with India.

Burma’s foreign minister, Wunna Maung Lwin, was in New Delhi last week on a four-day visit where he met with his Indian counterpart S.M. Krishna – the latter said after the talks that the two country’s “security interests are intertwined”, particularly along their lengthy shared border where India separatist groups shelter, sometimes on Burmese soil.

But India and Burma’s security relations go further, with India thought to be one of a handful of countries that still supplies weaponry to the Burmese, although this thought to comprise mostly artillery which is destined mainly for Burmese army camps in its northwest close to where Indian separatist groups are located.