The international community has expressed concern over fighting between Sudan and South Sudan. Fighting escalated when South Sudanese forces took control of the oil town of Heglig, which lies along the ill-defined border separating the countries.
Samantha Donkin, a spokeswoman for the International Organization for Migration, said her group was working to assist the estimated 1,300 South Sudanese refugees who became trapped in Heglig after leaving from Khartoum in late March.
"IOM is concerned at the (effect of) increasing tensions between the Sudan and South Sudan on returnees who become stranded on their way home," she said in a statement.
Members of the U.N. Security Council called on both sides to end the violence. U.S. Ambassador to the United Nations Susan Rice said, in a statement, she welcomed South Sudan's withdraw from Heglig last week but was concerned by Sudan's strikes on Unity state in South Sudan.
"Council members welcomed the withdrawal of the SPLA (Sudan People's Liberation Army) from Heglig, demanded an immediate halt to aerial bombardment by the Sudanese armed forces and urged an immediate ceasefire and a return to the negotiating table," she said in a statement.
The United Nations estimates around 35,000 people have been displaced by border fighting.