Tensions have been escalating between Sudan and its southern neighbour after South Sudan captured the Heglig oil field.
Sudan has since regained control of the facility. However, peace talks between Sudan and South Sudan have been suspended following the recent clashes. And Sudanese officials say those talks will not resume unless security issues are resolved.
Meanwhile, the Nuba mountains along the border remain a flashpoint. The rebel group, Sudan People's Liberation Movement-North (SPLM-N), says that it is fighting for the liberation of the Nuba people.
The SPLM-North is banned in Sudan. In the view of the Khartoum government, the group has been waging a proxy war against it with the backing of the authorities in Juba. And a former general says the SPLM-N is trying to topple the government in Khartoum.
Al-Jazeera's Zeina Khodr reports from Sudan.