Sri Lankan forces captured the Tamil Tigers' last major stronghold Sunday, confining the rebels to a narrow slice of jungle and ending their decade-long domination of the country's north. On Sunday afternoon, troops entered the coastal town of Mullaittivu, the last major town under the rebels' control and drove off the fighters inside. Army commander Lt. Gen. Sarath Fonseka said the bloody ethnic separatist war that has plagued Sri Lanka since 1983 was nearly over. But analysts warn that it is simply shifting from a conventional fight between two armies to a guerrilla war likely to be fought among the estimated 250,000 displaced civilians reportedly trapped in the northern jungles with the rebels. In recent weeks, the Sri Lankan army drove the rebels from their administrative capital of Kilinochchi, forced them to retreat from most of the de facto state they controlled in the north and boxed them into a shrinking pocket of land.