Separatist Tamil rebels fought intense battles against government forces trying to advance on the militants' de facto capital in northern Sri Lanka, killing at least 89 soldiers, a rebel-affiliated Web site said Thursday. The military disputed that death toll, saying that pitched battles in the north over the past two days had left 20 soldiers and 27 rebels dead. The TamilNet Web site reported that heavy fighting took place Wednesday around the rebel headquarters of Kilinochchi between the guerrillas fighting and government troops trying to advance into rebel-held territory. In the worst fighting, rebels repulsed advances by soldiers on the villages of Oottuppulam and Puthumurippu, west of Kilinochchi, killing more than 60 soldiers, the Web site reported, citing unidentified rebel officials. Separately, heavy clashes broke out to the south of Kilinochchi, killing an additional 29 soldiers, it said.