There are growing fears of civil war in South Sudan, with fresh clashes in a conflict that is deepening ethnic tensions in the world’s newest nation.
After fighting erupted around the capital Juba on Sunday night, government troops are now battling rebels to regain control of the key town of Bor.
The violence pits loyalists of former Vice President Riek Machar against the administration of President Salva Kiir.
Tensions have risen since Kiir sacked Machar in July.
Each man is from a different ethnic group, raising fears of civil war.
Latest reports say Machar has now urged the army to overthrow the president.
At least 500 people have been killed in the conflict. Thousands more
have taken shelter on the bases of UN peacekeepers in the nation which broke away from Sudan in 2011.
African mediators have been holding talks with President Kiir to try to broker peace.