Rwanda-backed rebels controlling cities in eastern Congo have forcibly closed settlement camps, leading to the displacement of more than 110,000 people in recent days, the U.N. and locals said Tuesday.

Analysts say the deadly march by Rwanda-backed rebels across eastern Congo could widen into a regional conflict drawing in even more countries, and the two nations most involved in the mineral-rich area might be the key to stopping the violence.

The takeover of Bukavu would constitute an unparalleled extension of territory under the M23’s control, as well as a further blow to Kinshasa’s authority in eastern Congo following the collapse of Goma,