The United States has ordered its non-emergency government personnel in South Sudan to leave the country because of security concerns, the State Department said on Sunday.

"Armed conflict is ongoing and includes fighting between various political and ethnic groups. Weapons are readily available to the population," the State Department said.

The United Nations rights agency said on Saturday that increased violence and political friction in South Sudan threatened the fragile peace process.

Earlier this month, security forces loyal to President Salva Kiir arrested two ministers and several senior military officials allied with Riek Machar.

Raised fears for the future

The arrests have raised fears for the future of a 2018 peace deal which ended a five-year civil war between forces loyal to Kiir and Machar that cost nearly 400,000 lives.

The State Department said violent crime including carjackings, shootings, ambushes, assaults, robberies, and kidnappings are common throughout South Sudan, including in Juba.

The area is very dangerous for journalists as well as US government employees, who are under strict curfew and must use armoured vehicles for nearly all movements.