The M23 has handed over more than 5,000 captured FARDC soldiers to the International Committee of the Red Cross.
According to the group, the handover took place on Monday at the Rugamabo camp in North Kivu Province.
The captured soldiers, taken during fighting on several fronts, will be repatriated to Kinshasa under the supervision of the Red Cross.
M23 described the transfer as a humanitarian gesture aimed at easing tensions and demonstrating its commitment to confidence-building measures in line with international humanitarian law.
The rebel coalition said the move reflects its willingness to support de-escalation efforts, particularly as mediation initiatives continue around the conflict in eastern Democratic Republic of the Congo.
However, the group accused the government in Kinshasa of failing to reciprocate such gestures.
It claimed authorities have refused to release detained M23 members and other individuals allegedly arrested arbitrarily because of their appearance.
The alliance also accused the government of violating ceasefire arrangements and conducting military actions against areas under its control, which it said have affected civilian populations and property.
The group called on mediators and international partners to take note of what it described as repeated ceasefire violations by the government of Félix Tshisekedi.
The conflict in eastern Congo has intensified in recent weeks, with clashes between government forces and M23, contributing to a worsening humanitarian situation in North Kivu and surrounding regions.