SRI LANKA ? Tamil rebels and Sri Lankan troops fought one of their fiercest battles in years Wednesday, battering each other with small arms and mortars in a confrontation that the military said killed 100 guerrillas and left 76 soldiers dead or missing.

The rebels claimed they killed more than 100 soldiers and lost only 16 of their fighters in a 10-hour firefight they characterized as a rout of the heavily armed government forces.

Either way, the battle was a serious blow to the government’s promise to capture the Tamil Tigers’ de facto state in the north, crush the rebel group and end the 25-year-old civil war in this Indian Ocean island nation by the end of the year.