The UN peacekeeping force in eastern Democratic Republic of Congo has warned of the risk of ethnically motivated attacks as conditions deteriorate in the region, haunted by the legacy of the 1994 Rwanda genocide and its aftermath.

United Nations Secretary-General Antonio Guterres on Tuesday spoke separately with the presidents of the Democratic Republic of Congo and Rwanda about the escalating conflict in eastern Congo, U.N. spokesperson Stephane Dujarric said.

The militia seized the pivotal city of Goma, threatening a new humanitarian crisis in a region that has suffered decades of fighting.

A rebel alliance claimed the capture of the biggest city in the Democratic Republic of Congo’s mineral-rich eastern region this week, pushing back against resistance from government troops backed by regional and UN intervention forces.

Rebels led by the M23 group claim to have taken control of Goma, a key city in the eastern Democratic Republic of the Congo.

Residents in eastern Congo’s largest city of Goma are fleeing after Rwanda-backed rebels claimed to have captured the regional hub from Congolese forces