The conflict between Sudan and South Sudan continues to escalate as the former nation declared a state of emergency along the border with the latter, reports The New York Times.
There have been a number of clashes in recent weeks between the two African nations as both vie for control of the region's oil. South Sudan contains most of the area's oil wells while the infrastructure to transport the hydrocarbon mainly resides in Sudan.
Earlier in April, South Sudan - which seceded from Sudan last summer - took possession of the oil-producing area of Heglig. However, Sudan was soon able to regain control of the area, according to the Times.
Further, Sudan has said that it captured a number of foreign nationals in Heglig, accusing them of being spies for South Sudan.
South Sudan responded, saying that the people were clearing land mines as part of a United Nations group and merely lost their way and thus were found in the region.
According to the BBC, oil development accounts for 98 percent of South Sudan's revenue.