Uganda has deployed an unknown number of troops to South Sudan in a bid to protect the fragile government of President Salva Kiir as a tense rivalry with his deputy threatens a return to civil war in the east African nation.

Tension mounts in South Sudan as power deal between President Salva Kiir and Vice President Riek Machar unravels.

The U.S. State Department has ordered nonemergency government personnel to leave South Sudan’s capital as tension escalates because of fighting in the north.

Uganda has deployed special forces to South Sudan's capital, Juba, to help President Salva Kiir to "secure it", Uganda's military chief Gen Muhoozi Kainerugaba has said. The move comes as tensions escalate between Kiir and his deputy Riek Machar,