Sources have indicated to NDTV that the threat is "specific" and Naval bases have been alerted.

Terror group Jaish-e-Mohammad may be planning to attack Indian Navy warships using deep sea divers, according to an intelligence alert that the Navy is seriously assessing.

The intelligence report, processed by India's Multi Agency Centre that coordinates intelligence between security agencies, indicates that a group of Jaish terrorists are presently trained in deep sea techniques in Bahawalpur, Pakistan, and may be planning to "target strategic assets of the Navy."

It is unclear whether "strategic" has been used in a generic manner to indicate a threat to Navy warships since it can also imply a threat to India's most sensitive military assets - its ballistic missile submarines, the INS Arihant and INS Arighat, which are designed to fire nuclear-tipped submarine launched ballistic missiles. Both submarines and the Russian-built nuclear attack submarine INS Chakra are based in Visakhapatnam.

Sources have indicated to NDTV that the threat is "specific" and Naval bases have been alerted.

Senior sources in the Navy have told NDTV that India's Naval bases and ports have a multi-layered security grid with sonar systems deployed on approaches to harbours which are specifically designed to detect deep sea divers. Navies around the world acknowledge the threat posed to capital warships when they are in port or anchored out at sea. Unable to manoeuvre in tight spaces, large warships cannot defend themselves effectively against underwater threats in confined spaces like ports and dockyards.

In 2,000, 17 US Navy sailors were killed when Al Qaeda terrorists rammed an explosives laden boat into the destroyer USS Cole when it was refuelling at the port of Aden in Yemen.