Leading human rights advocates, led by the Global Centre for the Responsibility to Protect, have written an open letter calling on the U.N. Security Council to take immediate action to prevent atrocities in Sri Lanka. A rebel force fighting the Sri Lankan government, the Liberation Tigers of Tamil Eelam, is refusing to let noncombatants leave the combat zone and is using the noncombatants as human shields. The Sri Lankan army has begun a final assault on the rebels that could lead to the deaths of thousands of civilians.

John Holmes, the U.N. Emergency Relief Coordinator, has said that “a bloodbath...seems an increasingly real possibility.” Navi Pillay, the U.N. High Commissioner for Human Rights, has stated that casualties may reach “catastrophic levels” if the fighting is not stopped. “At the core [of the responsibility to protect] is the obligation to act preventively to protect peoples from genocide, war crimes, crimes against humanity and ethnic cleansing, rather than waiting until atrocities have already occurred, as states have too often done in the past,” said the letter’s signatories.