Rwanda-backed M23 fighters have captured swathes of eastern DRC despite military support provided by several countries, including South Africa, to the Congolese army.

The wounded troops were part of a mission sent by the 16-nation Southern African Development Community (SADC) bloc in 2023 to help Kinshasa quell unrest in the mineral-rich east.

"The group of critically injured soldiers who needed urgent medical attention have been successfully repatriated," the South African National Defence Force (SANDF) said in a statement.

It was not immediately clear how many had arrived.

SANDF said the next batch of injured soldiers would return "during the course of the week".

A tally of those wounded would be given at the end of the exercise, SANDF spokesman Siphiwe Dlamini told AFP.

South Africa dominates the SADC force, which is estimated to number around 1,300, with Malawi and Tanzania also contributing soldiers.

Earlier this month, Malawi ordered its troops to prepare to withdraw from DRC.

South Africa has suffered 14 casualties in the raging conflict that has provoked fears of a regional war. Most of the casualties were part of SADC mission.

At least two of those killed were in a separate UN-mandated peacekeeping force.

The M23 group is supported by some 4,000 Rwandan soldiers according to UN experts.

It has wrested control of the South Kivu provincial capital Bukavu and Goma, the main city in the country's perennially volatile east.

More than 7,000 people have been killed in the fighting since January, DR Congo's Prime Minister Judith Suminwa Tuluka told the United Nations Human Rights Council in Geneva on Monday.

She said the number includes "more than 2,500 bodies buried without being identified", adding that another 1,500 bodies were still in the morgue.

AFP has not been able to verify these figures.