This advance could indicate M23 had renewed push towards Bukavu that the group launched after they seized Goma last week.

A Congo military court issued an international arrest warrant for Nangaa on Tuesday accusing him of war crimes and treason.

The capture of eastern Democratic Republic of Congo’s largest city displaced hundreds of thousands of people and fanned fears of a wider regional war.

Congo accuses Rwanda of using the M23 to pillage valuable mineral deposits. Rwanda says it is acting in self-defense and to protect ethnic Tutsis.

‘Staggering human toll’

The scale of the civilian harm was still emerging in Goma where people last week were caught in the crossfire and fighting destroyed buildings, overwhelmed hospitals and left bodies strewn in the streets.

The U.N. Office for the Coordination of Humanitarian Affairs on Wednesday estimated at least 2,800 people died in Goma.

“The human toll is staggering. We and our partners are struggling to assess the full extent of the situation,” spokesperson Jens Laerke said via email.

International Criminal Court prosecutors said they were closely monitoring events after reports of possible war crimes in the battle for Goma.

The International Committee of the Red Cross said its medical warehouse in Goma was looted last week and would take months to restore.

The city’s bishop, Willy Ngumbi, on Wednesday deplored damage to a maternity ward from explosives and called on Rwanda, Congo and Burundi — which also has troops in the region aiding Congo — to hold talks to prevent an escalation of the conflict.

In Congo’s capital Kinshasa, lawmakers in the National Assembly held a lengthy closed-door extraordinary session to discuss the crisis ahead of a summit with eastern and southern African leaders in Tanzania this weekend.

A diplomatic source said Rwanda opposed the presence of troops from the 16-member Southern African Development Community that are supporting Congo and which extended their mission late last year.

Despite renewed fighting, Malawi on Wednesday cited the ceasefire in its order for its troops to withdraw from the force.