North Sudan and the semi-autonomous south have tried to win control over Abyei’s nearby oilfields and a pipeline supplying crude to Sudan’s Red Sea coast.
At least one person died in Friday’s clashes, which came less than two weeks after UN officials said that thousands of civilians were returning home after the fighting in May.
The precise circumstances that led to the fighting are unclear, but one official said that an argument in a marketplace between a store seller and a northern soldier led to the violence.
Local officials in Abyei told AFP on Sunday that the violence was over and stressed that the fighting had been localised and without heavy weapons.
As well as the dispute between the Khartoum government in the north and the government of southern Sudan over Abyei, the administrations are also contesting the grazing rights for migratory Arab herders from the Messeria tribe, aligned largely with the north.
Rival politicians from north and south agreed in June to conduct joint patrols and share an interim administration of Abyei.
In 2011 autonomous south Sudan is scheduled to vote on whether to break away as an independent state or remain united with the north.
Abyei is to hold a separate vote on whether to retain its special administrative status in the north or become part of the south.