Images of families from Sudan's Darfur region crossing the border into neighboring Chad, as heavy fighting continues in Sudan's capital, Khartoum, despite an announced truce between the army and paramilitaries, whose clashes have brought the country to the brink of a "catastrophe" and could prompt "more than 800,000 people" to flee the country, according to the UN. At least 20,000 Sudanese have sought refuge in Chad since the conflict began, of whom about 5,000 have registered, according to the UN High Commissioner for Refugees (UNHCR). IMAGES