(Updates with details and fresh quotes) By Ranga Sirilal COLOMBO, Sept 11 (Reuters) - Sri Lanka's military claimed a major victory against Tamil Tiger rebels on Tuesday, saying it sank three vessels carrying war equipment including three light aircraft and a bullet-proof car. "We consider this is the biggest victory Sri Lanka's navy has achieved so far," Commander Wasantha Karannagoda told reporters in Colombo, adding between 40-45 rebels were also killed in the clash. The Tigers, fighting for an independent state for minority ethnic Tamils in the north and east, were not immediately available for comment. The navy said the destroyed vessels were carrying three light aircraft, a bullet-proof vehicle for rebel leader Velupillai Prabhakaran and other war-related material. The clash was the latest in a spate of land and sea battles, ambushes and air raids between the armed forces and Liberation Tigers of Tamil Eelam (LTTE) rebels. "When we challenged these vessels, they didn't respond so we had to follow internationally accepted rules of engagement," Karannagoda said. "They opened fire. We had no choice but to fire and destroy the vessels." The clash follows a new offensive launched by the Sri Lankan military to drive the Tamil Tigers rebels from the northwest Mannar area, after evicting them from jungles in the east of the island. An estimated 5,000 people have died since last year in renewed fighting after a peace process collapsed. In the civil war that erupted in 1983 about 70,000 people have been killed and hundreds of thousands displaced. Additional reporting by Shihar Aneez
