Machine guns, mortars, a rocket-propelled grenade launcher, an anti-tank weapon and explosives were among the items seized, the website reported.
The rebels reportedly launched the offensive in memory of Lieutenant Colonel Kadaafi, a commander of the Sea Tiger Special Engineering Division, who was killed two months ago.
The LTTE has its own naval unit, a rarity among guerrilla outfits anywhere in the world, and operates a fleet of fast boats as well as merchant vessels used for gun-running.
The rebels have previously used explosives-laden boats to ram and sink Sri Lankan navy craft in spectacular suicide attacks and have also staged attacks inside key ports in the country.
They have also been accused of attacking local and foreign owned merchant vessels operating in the troubled north-east.
In their previous attack on the navy on May 29, the Tigers said they killed 13 sailors, a claim denied by the military which in turn said 16 rebels had lost their lives.
Casualty fi