UN mission transports South Sudan fighters for emergency treatment

The rebel fighters had crossed into the DRC and "were found in bad condition and evacuated to health facilities," UN spokesman Stephane Dujarric said.

Many were in critical condition and were helped "on purely humanitarian grounds so that they can receive urgent medical assistance," he said.

The fighters, who surrendered their weapons before boarding UN helicopters, were chased from South Sudan's capital of Juba in July after heavy fighting with forces loyal to President Salva Kiir.

Machar, who is the country's former vice president, was also injured and aided by the DRC mission, which is also known by its French acronym MONUSCO.

The rebel leader was then turned over to DRC authorities and is currently undergoing medical treatment in the Sudanese capital of Khartoum.

Fighting in South Sudan began with a dispute between Kiir and Machar in December 2013.

Since then, the country has been split along roughly tribal lines in a conflict characterized by massacres, rape, attacks on civilians and the use of child soldiers.

Tens of thousands have been killed since December 2013 and 2.5 million have fled their homes. Twice that number rely on food handouts to survive, with the UN calling the levels of food insecurity "unprecedented."