The two-day clashes erupted over the weekend after some armed youths in the Greater Tonj area engaged with security forces.
Clashes that erupted between soldiers and civilians during a disarmament exercise in the central South Sudanese town of Tonj have left 127 dead,
"On the latest, the number of those killed, I can confirm to you that it rose to 127," army spokesperson Major General Lul Ruai Koang said, adding that 45 of those killed were security forces and 82 were armed youths from the area.
Koang told Reuters the two-day clashes erupted over the weekend after some armed youths in the Greater Tonj area started engaging the security forces.
It was not immediately clear what sparked the fight, he said, adding that an investigation has been started.
The wounded security personnel were flown to the military hospital in the capital Juba for treatment, he said, adding that calm had returned to the area as authorities restored order.
The national government, formed this year after a deal to end a conflict that broke out in 2013, launched a disarmament exercise in Tonj county last month, saying that armed militias in the area were driving inter-communal violence.