The naval assault came amid reports LTTE leader Velupillai Prabhakaran and his top aides might try to flee from the last rebel-held enclave in the island nation's northeast, the Press Trust of India reported.
Sri Lankan officials also said they had stopped seven attempts by the LTTE to retake fortifications in Rektavaikkal whose capture by the government has left the rebels vulnerable.
A naval spokesman told PTI the military noticed six rebel boats sailing out of the coastal enclave and sank all of them, killing all 25 LTTE personnel on board. The spokesman said four of the craft were packed with explosives for a possible suicide strike against Navy ships to clear the way for the other two boats to escape.
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