The U.N.’s top human rights body has condemned Rwanda’s support of rebel fighters across the border in eastern Congo and ordered a team of experts to examine rights violations in the region

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.

M23 rebels said they have advanced into Goma, a large city in the eastern Democratic Republic of Congo. Hundreds of thousands of residents have been displaced.