Twenty-one soldiers returned Tuesday and 106 more on Wednesday, South Africa National Defence Force (SANDF) spokesman Prince Tshabalala said.

They were part of a mission deployed by the 16-nation Southern African Development Community (SADC) bloc in 2023 to support the DRC government in the east, where the Rwanda-backed M23 armed group has made significant territorial gains.

"We have admitted four patients (who are) critical," Tshabalala said. Seventeen others had moderate injuries. Some of the others who returned required "psychological and social intervention".

The injured soldiers had received treatment in DRC hospitals and travelled through Rwanda for the evacuation, Tshabalala told AFP.

Calls have been mounting for the entire South African contingent to return home after 14 soldiers were killed in the conflict late January.

Most of the 14 were part of the SADC mission but at least two were members of a separate UN-mandated peacekeeping force.

South Africa had deployed more than 1,000 soldiers in the DRC, according to reports and analysts, although officials have not given precise numbers.

It dominates the SADC force, which includes smaller numbers of soldiers from Malawi and Tanzania.

The centre-right Democratic Alliance (DA) party -- a coalition partner in the government of national unity -- and the radical-left Economic Freedom Fighters (EFF) have in a rare unison called for the "immediate" withdrawal of the troops.

The M23 group has gained 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, DRC Prime Minister Judith Suminwa Tuluka said Monday, although AFP has not been able to verify the figures.