Who is fighting in South Sudan and who can stop it?

Days of fighting in South Sudan’s capital Juba is some of the worst seen since civil war broke out in the world’s newest nation in December 2013.

Pitting soldiers loyal to President Salva Kiir against troops backing his longtime rival Vice-President Riek Machar — who technically ended rebellion in April to forge a unity government — the fighting has also drawn in other forces.

Here are some of the key players in the violence: some driving it and others trying to stop it.

– Kiir and Machar -Kiir and Machar are former rebel leaders who rose to power during Sudan’s 1983-2005 civil war between north and south — a conflict in which the two men fought each other — before South Sudan won independence in 2011.

They come from the south’s two main ethnic groups — Kiir from the Dinka people and Machar from the Nuer — tribes that are themselves split into multiple and sometimes rival clans.

UN experts say Kiir and Machar are both responsible for most of the violence committed during the war, which has seen tens of thousands killed.

Civil war began in late 2013 when Kiir accused Machar of plotting a coup.

Following an August 2015 peace deal Machar returned to Juba in April, along with 1,500 troops who are based in basic camps on the outskirts of the city and were only permitted to carry light weaponry.

Kiir’s army — equipped with tanks, artillery and attack helicopters — were supposed to withdraw from the city leaving only a similar-sized force behind.

– Hardliners -The fighting has fragmented and multiple militia forces now pay no heed to either Kiir or Machar.

There are also reported divisions within both camps. Both Kiir and Machar were at the presidential palace to issue a joint appeal for calm on Friday when heavy fighting erupted outside.

Analysts say hardliners on both sides never supported the August 2015 peace deal and instead want to end the conflict through military means.

Key figures include army chief Paul Malong, a top general and powerful politician who commands an ethnic Dinka militia. He is a long-time ally of Kiir and opposes power-sharing with Machar.

Machar’s authority over generals and troops is also in question, in particular his command over ethnic militia such as the so-called ‘White Army’, a fearsome force of cattle-raiding youth who pay little heed to anyone but their direct leaders.

– Neighbouring nations -Past peace efforts have been led by regional nations, including the East African bloc IGAD. Ethiopia and Kenya have hosted multiple rounds of peace talks.