Pibor is relatively calm after fighting erupted between the Cobra forces and the SPLA two days ago, an official has said.
At least nine soldiers were killed in the Tuesday attack.
The Boma State coordinator, Gabriel Amakori, says civilians who had fled the fighting are now returning home.
“The situation is calm and the governor is already there in Pibor,” Mr Amakori told Eye Radio. “The elements who attacked the town have run to the bushes.”
The cause is still not clear; however, local officials have been reporting tension between the guards of the governor, Baba Medan, and forces loyal to former chief administrator of the area, General David Yau Yau.
Meanwhile, the medical charity MSF says there is a need for medical services in Pibor.
The charity also says its compound in the area was looted during the fighting.
“There are critical emergency medical needs right now in Pibor, and really limited capacity to respond and save lives,” says Corinne Benazech, MSF Head of Mission, in a statement.
“We need to assess the damage and looting of the MSF health center, but if we cannot restart activities this could make a bad situation catastrophic, since MSF provides the only healthcare in the area.”
The MSF says its staff have been forced to move to an UNMISS base due to the heavy gunfire in the area.
The charity says it is currently providing emergency treatment to about 35 patients, but it lacks surgical equipment to provide the urgent treatments required.