The U.N. secretary-general appealed Thursday for peace in the Democratic Republic of Congo, where a recent escalation of fighting between rebels and the national army has killed at least 2,900 people and displaced tens of thousands.

“It is time for mediation. It is time to end this crisis. It is time for peace,” Antonio Guterres told reporters. “The stakes are too high.”

A senior U.N. official in the DRC said Wednesday that nearly 3,000 people have been killed in recent fighting between the M23 movement and the national army over the eastern city of Goma, which fell to the rebels on Jan. 27.

Guterres said hundreds of thousands of civilians have been forced to flee their homes, and there are credible reports of grave human rights abuses, including rape.

“The humanitarian situation in and around Goma is perilous,” he said.

The M23 is looking to expand its territorial gains and is reported to be about 50 kilometers (30 miles) outside the South Kivu capital of Bukavu. Heavy fighting has been reported this week along the main route between the towns of Kinyezire and Nyabibwe.

Guterres spoke a day ahead of a planned crisis summit in Tanzania of the East African Community and the Southern African Development Community. The secretary-general also said he would travel next week to the Ethiopian capital, Addis Ababa, to participate in an African Union Peace and Security Council summit to discuss the DRC.

“As the summit in Tanzania gets under way, and as I prepare to leave for Addis Ababa, my message is clear: Silence the guns. Stop the escalation,” he said.

The U.N. chief was adamant that there is no military solution to the crisis and called on the signatories of the Peace, Security and Cooperation Framework for the DRC and the region to honor their commitments.

The Congolese government has repeatedly accused Rwanda of supporting the M23, a claim that Rwanda denies but which U.N. observers have said is true.

Kigali, in turn, alleges that Kinshasa collaborates with the Democratic Forces for the Liberation of Rwanda, or the FDLR, a Hutu armed group with ties to the perpetrators of the 1994 Rwandan genocide, an allegation the DRC rejects.

The DRC government has officially designated the M23 as a terrorist organization, while the United Nations and the United States classify it as an armed rebel group.