Sudan and South Sudan have broken off security talks after failing to agree on a demilitarised zone along their disputed border. After 10 days of talks, the two sides were unable to agree on Friday where to draw a demilitarised buffer zone along the 1,800km-long border. Khartoum's delegation accused South Sudan of making new land claims, most importantly to the Heglig oilfield whose output is vital to Sudan's battered economy. The southern army had temporarily occupied Heglig during the recent fighting.