A Sri Lanka navy fast attack boat was destroyed on Saturday when it hit a suspected sea mine laid by Tamil Tiger rebels off the northeast coast, with 10 of the 16 crew still missing, the military said.
But pro-Tamil sources said the boat was destroyed by a suicide squad of so-called black Tiger fighters, with three rebels killed in the sea clash.
The military said the boat struck a mine during an early morning patrol by two navy craft in darkness near Nayaru area, around 300 kms (185 miles) north of the capital Colombo.
"We suspect it was an LTTE (Liberation Tigers of Tamil Eelam) sea mine," navy spokesman Commander D.K.P Dassanayake told Reuters, saying the explosion happened around 2 am local time.
"The commander of the boat said it was raining and he heard an explosion, so we suspect it's a sea mine explosion as there were no LTTE boats around that time and there wasn't any confrontation," Dassanayake said.
The pro-Tiger website said rebel suicide fighters destroyed the boat.
"Elite Black Sea Tigers, engaged in a confrontation with a fleet of the Sri Lanka Navy in the seas off Mullaiththeevu, attacked and sunk a Dvora Fast Attack Craft," the website said, citing Tiger sources in Vanni.
Both sides regularly make conflicting claims to boost frontline morale, and reports are impossible to verify since Nordic peace monitors keeping watch over a shaky ceasefire pact left the island this year after a resumption in fighting.
President Mahinda Rajapaksa formally scrapped a six-year truce in the country's 25-year civil war in January, accusing the rebels of using the peace to rearm. The navy ship was the second sunk by suspected Tigers since then.
The military has been intensifying its campaign against the Tigers, who are fighting for an independent homeland, pressing forward in their northern strongholds and aiming to defeat them by year's end.
In a separate incident, two government soldiers were killed and six others injured when their bus hit a Tiger landmine in the Mannar area late on Friday.
That bought the death toll in fighting this week to 143 rebels and five soldiers, with a search was still underway for the 10 missing crew from the navy attack craft.
The Tigers have hit back against the military offensive with regular attacks increasingly aimed at civilians and normally using roadside bombs. An estimated 70,000 people have died since the war began in 1983. (Reuters)
Tiger rebels sink Sri Lanka navy boat