The renewed clashes erupted midweek in Kolang Payam of former Bor County, following last year's disagreement that left 20 people dead, Jonglei State Information of Minister Jacob Akech Deng told Xinhua.
"The inter-clan clashes happened on Wednesday and drag up to Thursday, leaving 15 dead and wounding eight others on both sides," Akech said.
The clashes erupted again over ownership of grazing land and the naming of a village.
Deng said one group attacked the other clan in retaliation after the killing in December last year over the naming of a village.
He said the local authorities have intervened by deploying heavy security force along a previous created buffer zone to monitor the violators and help restore calm in the area.
Deng added that the regional government has issued stern warnings to the local chiefs to apprehend perpetrators of the latest round of fighting.
"I and the deputy governor went to the ground this morning to talk to the chiefs and villagers, and warned them against staging revenge killings and to ask them to allow the authorities to handle the matter without loss of lives," he said.
The Jonglei region has suffered decades of communal and tribal violence, mainly caused by rivalry over livestock and grazing land.
At least 22 people were killed and 18 others wounded in December last year when members of the Nyara clan and other clans of Abii community fought over ownership of land in the same area.