Sporadic gunfire is ringing out in the South Sudan capital, Juba, in what appears to be clashes between sections of the country's military.

An Associated Press reporter saw heavily armed soldiers patrolling the streets of Juba early Monday amid sporadic gunfire emerging from Juba's main army barracks.

It was not possible to get a comment from official government or military spokesperson because of the poor telephone network.

There has been political tension in the world's youngest nation since South Sudan President Salva Kir sacked Riek Machar as his deputy in July. Machar has expressed a willingness to contest the presidency in 2015.

UPDATE: South Sudan's army spokesperson Phillip Aguer has told the BBC that calm is returning to Juba after fighting overnight and this morning.