At least 30 people, comprising both Sri Lankan Navy personnel and the Tamil Tiger rebels, were suspected killed in a fierce sea battle between the two sides in the northern sea waters on Thursday evening, pushing the island nation further towards a full-scale civil war.

According to military sources, the battle was triggered off in the seas off Vettilaikerny in the Northern Jaffna peninsula, when a flotilla of at least 16 Sea Tiger boats, including a couple of suicide boats, encountered the fast attack craft of the Sri Lankan navy while they were providing escort to a passenger ship Green Ocean, carrying over 300 stranded civilians from Trincomalee to Kankesanthurai.

"The Navy destroyed at least eight LTTE boats and is believed that at least 25-30 Sea Tiger cadres were killed," the military sources said. Top naval sources said the Navy also lost two Dvora fast attack crafts during the battle that lasted for over two hours.

"Four sailors survived and were rescued while the search operation to rescue the missing sailors after the battle," a naval official said, confirming that the passenger ship was safely on its way to the Kankesanthurai harbour.

Meanwhile, the Tamil Tiger rebels said the fresh clash with the Sri Lankan Navy left at least 25 Sri Lankan troopers and five Sea Tigers killed.

"A Sea Tiger flotilla clashed with Sri Lanka [Images] Navy (SLN) in the Northern waters killing 25 SLN troopers, capturing 4 troopers alive and destroying two Dvora Fast Attack Crafts," a pro-LTTE Tamilnet website reported, quoting LTTE Military Spokesman Irasiah Ilanthirayan as saying.

According the LTTE spokesman, the Sea Tigers seized two fast attack crafts of the Sri Lankan navy and dismantled all the armament, including a 23 mm canon and an AGL gun before destroying them.

Claiming that a 23 mm Canon, five PK-LMGs, four 50 calibre guns and an auto HK grenade launcher with ammunition were seized by the Sea Tigers, the LTTE spokesman said a dead body of a naval sailor was recovered by the rebels and taken to the Wanni.