REPUBLIKA.CO.ID, JUBA -- The U.N. envoy for South Sudan called on Monday for an end to fighting that erupted overnight between soldiers in Africa's newest nation and said she was in touch with the country's leaders.

"I urge all parties in the fighting to cease hostilities immediately and exercise restraint," U.N. Special Representative of the Secretary-General Hilde Johnson said in a statement.

"I have been in touch regularly with the key leaders... to call for calm."