The UN will investigate the deaths of nine people allegedly shot by South Sudanese soldiers in Western Bahr el Ghazal state in the country's northwest.
"UNMISS (the UN mission in South Sudan) is investigating the use of force and other reports of violence in order to
establish the facts behind these tragic events," UNMISS said in a statement on Friday.
"Nine civilians have been confirmed killed and many more injured in incidents involving demonstrators and members of the security forces," the statement said.
The incident on December 8 was captured in an amateur footage exclusively accessed by Al Jazeera in which soldiers are seen firing at a crowd of unarmed demonstrators in Wau, capital of Western Bahr el Ghazal state.
South Sudan's Civil Society Alliance, an umbrella group for local civil society organisations, quoted witnesses saying the demonstrators had been unarmed and protesting peacefully.
It began when the army was sent to dismantle road blocks set up by civilians protesting against plans to move the municipal council headquarters outside Wau.
Ateny Wek, spokesman for the Civil Society Alliance, said two more people had died from their injuries, bringing the death toll to eleven, with scores of others injured.
"It was barbaric for the state authorities to use live ammunition. They were marching peacefully towards state
government headquarters. We have eyewitnesses," Wek told Reuters.
South Sudan's government has been struggling to reform its soaring security services since it split from Sudan in July last year after a long civil war that has left the new country awash with weapons.
South Sudan's army, an assortment of poorly-trained former guerrilla fighters known as the SPLA [Sudan People's Liberation Army], have often been accused of abuse against civilians by human rights groups.
According to the UN, an estimated 2,400 people have been killed in rebel and tribal violence since independence.