Dozens of South Sudan's citizens were killed in violent clashes between tribal groups.

The violence took place in Yambio, capital of western Equatoria state, on Saturday, local media quoted Information Minister Charles Kisanga as saying.

The clashes forced most people in the city to flee to a nearby United Nations mission base.

The army has been accusing elements of youth groups in the state of allegedly rebelling against president Salva Kiir’s government. Tensions have reportedly remained high on Sunday in the state capital.

South Sudan plunged into violence in December 2013, when fighting erupted between troops loyal to president Kiir and defectors led by his former deputy Machar.