Fighting has broken out on the border between Sudan and South Sudan, shortly after the South pulled out of a disputed border town, BBC reported. . Sudan has confirmed there had been clashes, which come after 10 days of fighting over the oilfield town of Heglig. On Monday, a Sudanese warplane dropped bombs near the South Sudanese border town of Bentiu, killing at least one. Satellite pictures of the Heglig area released on Sunday suggest key oil installations were badly damaged in the fighting and are no longer operating. The area north of the disputed border provides most of of Sudan’s oil output, and is a crucial part of its economy.