The Sri Lankan navy waged a short sea battle with Tamil Tiger militants Saturday evening, quickly sinking two rebel boats and killing six people on board, the military said, according to AP. The fighting occurred about 20 kilometers (10 miles) off Sri Lanka's northwest coast, when naval vessels ordered two small boats they suspected of belonging to the rebels to stop and then fired warning shots, said naval spokesman Cmdr. D.K.P. Dassanayake. The boats responded by firing a rocket propelled grenade. The navy fired back and sank them, he said. Sailors said a total of 10 people were on the two boats, he said. It was not immediately known what happened to the four others. The Tamil Tigers, who control a de facto state in parts of northern Sri Lanka, have a significant fleet of boats that they use to smuggle arms and carry out attacks against the government. Earlier Saturday the military said soldiers recovered two explosive belts, commonly used by suicide bombers, and other bomb-making material from the country's restive northern peninsula. The two belts, six bombs and detonators were found hidden near a Hindu temple in northern Jaffna peninsula after a tip from a civilian, an official at the Defense Ministry information center said on condition of anonymity in line with policy.