The Youth Leader in Ikotos County in Eastern Equatoria State says all the mobile phone networks in the area have been disconnected since Friday.
This follows a clash last week between the SPLA soldiers and civilians; at least three people were killed.
The State Minister of Information said civilians attacked an army barrack on Thursday, accusing soldiers of killing a businessman.
Mr. Lomili Mathias says youth leaders cannot communicate with their people on the ground about the situation.
He told Eye Radio the state government sent more soldiers to the county before disconnecting the network.
“They will tell you go back if you want to go from Torit to Ikotos. And even if anybody wants to come out of Ikotoz they will also tell you,” Mr Mathias said.
“So everybody is just staying in one place. If there wasn’t any problem, why should people be prevented from free movement?”
For his part, the State Information Minister, Mark Akio, said he could not give any information about the situation in the area.
But he added that the state government has sent a team of officials to the area to assess the situation.
“They need to come and then give us official report to let us know exactly what happened there.”
The youth leader says they are now concerned about the security of the civilians in the county.