Separatist Tamil Tiger rebels claimed to have killed at least 100 soldiers in the latest fighting in northern Sri Lanka, and army officers said more than 400 soldiers were wounded. President Chandrika Kumaratunga ordered that all news reports on Sri Lanka's civil war be cleared by military censors. Earlier, the guerrillas' clandestine radio said they had lost 20 fighters as they beat back a government offensive Thursday. The military spokesman would not confirm the casualties, but reported heavy fighting after government troops attacked rebel defenses near Kilinochchi, 170 miles north of Colombo, the capital. The two-pronged assault aimed to wrest the region's main highway from guerrilla control. Some army officers, speaking on condition of anonymity, said 34 soldiers were killed and 420 wounded in 24 hours of fighting that saw troops advance only half a mile.