Intelligence reports are warning of terror attacks through the sea route, officials and anti-terrorism experts say, weeks after an unrelated but chilling reminder: the latest issue of Al-Qaeda's main training manual issued an exhortation for maritime strikes.
The declaration last month in Al-Battar, the main training journal for the international terror group, made no mention of South Asia. But Indian officials say there are already increasing fears of anti-India groups infiltrating from or carrying out an attack along India's sprawling coastlines, especially after the sharp reduction in militant infiltration and attacks in Jammu and Kashmir.
"We have seen significant thinking and investment on the part of jihad groups to operate in the maritime domain. This is a recent development," international terrorism expert Rohan Gunaratna told the Hindustan Times from Singapore.
"Off-shore attacks are more difficult to carry out. They require more investment and planning. But they are more dramatic, and it will be something spectacular - which will be something new in the Indian context," Gunaratna said.
Protecting sea routes is crucial. The sea accounts for 90 per cent of India's trade by volume, and more than three-fourths by value, according to the Indian Navy. Between April and December last year, India's total imports and exports were valued at Rs 1,000,000 crores.
But the sprawling land mass makes foolproof surveillance virtually impossible. India has a coastline of 5,420 kilometres touching 12 states and union territories (UTs), apart from 1,197 farflung islands, accounting for 2,090 more kilometres of shores.
On Thursday, Defence Minister AK Antony said there were intelligence reports of militants planning a strike. "There are reports about terrorists of various tanzeems (groups) being trained and (the) likelihood of their infiltration through sea routes," Antony told Parliament.
The biggest maritime terror attacks so far were the bombing of the USS Cole in 2000 and of the French oil tanker Limburg in 2002, both blamed on the Al-Qaeda. The LTTE has been known to carry out several attacks using explosive-laden motorboats in Sri Lanka.
Beyond Indian waters, Indian defence officials have in recent weeks pointed to the threat from the seas in the Indian Ocean Region, that spans 736 million square miles.
"The IOR has become the de facto home of global terrorism with many regional states covertly or even inadvertently aiding and abetting subversive elements," Navy chief Admiral Sureesh Mehta said last month. Coast Guard director general Vice Admiral Rusi Contractor has expressed similar concerns.
"For India, oil supplies are the most vulnerable. Militants could attack oil supplies coming in from West Asia or at the Bombay High," anti-terrorism expert B Raman said by telephone from Chennai. "There could be attacks on ports or landing points, because it is much more difficult to attack ships at sea, and there is US Navy presence in the area."
The Ministry of Defence has suggested forging agreements with neighbouring countries and other littoral states to share information to stave off threats from the sea. India and South Africa are considering a system of regional cooperation in the IOR.