Congolese authorities and a civil society group say they found mass graves in an area of eastern Congo that the M23 rebel group has recently withdrawn from, as fighting in the region escalates despite a U.S. mediated peace deal.

The M23 rebel group is advancing toward eastern Congo’s largest city of Goma.

A Congolese governor says at least 78 people have died when an overcrowded boat with 278 passengers capsized on Lake Kivu in eastern Congo.