UNHCR has reported that Sudanese refugees are again fleeing Darfur for camps in neighbouring eastern Chad, while High Commissioner António Guterres warned the UN Security Council in New York of a "much greater calamity" in the region unless bold measures are taken soon. The UN refugee agency chief noted that the insecurity in Darfur has now spread across the border to Chad, where last Friday armed rebels took several government officials hostage and attacked the village of Guéréda, where the UN refugee agency is caring for more than 25,000 Sudanese refugees in two camps.