The navy sank nine Tamil separatist vessels Wednesday in a fierce battle off Sri Lanka's northwest coast that killed 40 rebels and one naval officer, the military said. One navy craft sank, the rebels said.
Separately Wednesday, ground battles in the north left 26 guerrillas and two soldiers dead, the military said.
The sea clash erupted early Wednesday after naval patrol boats attacked a rebel flotilla transporting weapons off northern Mannar district, said the military's spokesman, Brig. Udaya Nanayakkara.
Backed by helicopter gunships, the navy sank nine of the 16 rebel boats, killing 40 guerrillas, Nanayakkara said.
"One navy craft was also severely damaged as two suicide boats rammed into it," he said, adding that at least one navy officer died and 10 sailors were missing.
The rebels said their fighters sank one naval craft and damaged two others in the three-hour clash, according to an e-mailed statement from rebel spokesman Rasiah Ilanthirayan. Four Black Tigers, the rebel group's suicide fighters, died in the attacks, it said.
Calls to Ilanthirayan for comment went unanswered Wednesday.
The two sides often give widely divergent death tolls, exaggerating their enemies' casualties while undercounting their own. No independent confirmation of the battle was available.
On Tuesday, the navy spotted an Indonesian ship drifting about 100 miles off the east coast Tuesday morning, and troops boarded the ship to investigate, a defense ministry official said on condition of anonymity because he was not authorized to speak to the media.
The navy was questioning the 12-member Indonesian crew, the official said Wednesday, adding it was trying to determine if the ship was linked to the Tamil Tiger rebels, who occasionally use foreign ships to smuggle arms.
In September, the navy claimed it sank three rebel ships packed with weapons and light aircraft, nearly destroying what remained of the separatists' smuggling fleet.
The Indonesian ship's captain said his vessel was sailing from Mumbai, in western India, to Thailand and the vessel started drifting when it ran out of fuel, according to the official, who declined to give further details.
Meanwhile, soldiers fought a series of gun battles with Tamil Tigers along the northern front lines Wednesday, killing 26 rebels, the official said. Fighting killed two soldiers and wounded 12 others.
There was no comment from the rebels on the ground battles. Independent verification of the military's claims was impossible because the region is off limits to the media.
Fighting across northern Sri Lanka — where the separatist rebels control a de facto state — has intensified in recent months.
The Tamil Tiger rebels have been fighting since 1983 to create an independent homeland for Sri Lanka's ethnic Tamil minority after decades of discrimination from governments dominated by the Sinhalese majority. An estimated 70,000 people have been killed in the fighting.