GOMA, Congo (AP) — Fighting between the Congolese army and the M23 rebel group resumed in eastern Congo in yet another ceasefire violation ahead of potential mediation talks, both groups said.

The army said in a statement it inflicted heavy losses on the rebels in the Lubero territory of North Kivu province Monday, including several dead and wounded. An M23 spokesperson said on X the group also was attacked by the army early Tuesday.

M23 is one of a 100 armed groups that have been vying for a foothold in mineral-rich eastern Congo near the border with Rwanda, in a conflict that has created one of the world’s largest humanitarian crises. More than 7 million people have been displaced.

Congo and the United Nations accuse Rwanda of backing M23. Rwanda denies the claim, but in February admitted that it has troops and missile systems in eastern Congo to safeguard its security, pointing to a buildup of Congolese forces near the border. U.N. experts estimate there are up to 4,000 Rwandan forces in Congo.

Last week, Congo and Rwanda's foreign ministers agreed on the terms and conditions of the disengagement of Rwandan forces in eastern Congo.

In July, Congo signed a ceasefire with M23, which came into effect in August, but fighting has resumed since. Earlier this month, the United States said it was “gravely concerned” by ceasefire violations by M23 rebels.

The resumption of fighting comes as Congo's President Felix Tshisekedi and Rwanda's President Paul Kagame are set to meet on Dec. 15, according to the state news agency of Angola, which has been mediating the conflict. It would be their first official meeting since last year.