M23 is one of about 100 armed groups that have been vying for a foothold in mineral-rich eastern Congo near the border with Rwanda, in a conflict that has created one of the world’s most significant humanitarian crises. More than 7 million people have been displaced.

Rwanda-backed rebels battling Congo’s army have pushed into a strategic, mineral-rich town in the east, ignoring calls for a ceasefire this week by the Congolese and Rwandan presidents as the M23 rebel group expands its footprint in the conflict-torn African country.