Sudanese soldiers have agreed to ease tensions by withdrawing from the town of Abyei, where fighting left one dead, UN officials say.
Thousands of people fled the disputed oil town after fighting between the army and the police on Friday.
The details remain unclear, but fighting seems to have broken out after police intervened in an argument between a soldier and a trader.
The town is now reported quiet, but people are said to be nervous.
The head of the UN in Abyei Chris Johnson said the joint north-south army unit had agreed to withdraw to its new headquarters north of the town, the BBC's Amber Henshaw reports.
She said an inquiry would be launched to find out exactly what had happened on Friday, when fighting broke out in Abyei's market place.
Abyei has suffered a loss of confidence since fighting in May
Local officials say it started with an argument between a soldier from the north-south army, and a market trader; the police intervened and shots were fired.
One soldier from the north is said to have been killed, and nine other people, including two civilians, wounded.
The situation is now said to be calm but officials say thousands fled the town following the violence.
"We think 8,000 or 9,000 have left the town," Abyei's secretary for public utilities Juac Agok told Reuters news agency.
"In itself it was a small incident. But it has caused a lot of tensions because of what happened in May," he said.
Fighting then began after an argument at a checkpoint but quickly escalated because of long-standing unresolved tensions, dating back to a two-decade civil war between the north and south.
A peace deal ended the conflict in 2005 but could not resolve the boundary for the oil-rich area.
Both sides claim it as their own and have remained at odds over the demarcation of the town.