Immigrants from the rival Sudans are bearing much of the brunt of the fraying relationship between the two countries, as many people are forced by authorities to leave their homes behind.
Officials in bordering White Nile state in Sudan have declared about 15,000 South Sudanese residents in the city of Kosti as a security threat and ordered their expulsion by May 20.
Estimates say up to 500,000 South Sudanese still live in Sudan without legal documentation to stay.
Meanwhile, recently hundreds of Sudanese have been forced to return from South Sudan.
The fighting has made travel by road difficult and direct flights between the two countries have also been cancelled.
Thousands are now relying on humanitarian aid, but the mutual mistrust between the two governments has hampered the work of humanitarian agencies.
Al Jazeera’s Zeina Khodr reports from Khartoum.