The United Nations envoy in the Democratic Republic of Congo warned Wednesday that fighting in the east of the country could spiral out of control.

The vast mineral-rich DR Congo is struggling to contain dozens of armed groups in the east, many of which are a legacy of two regional wars a quarter of a century ago.

A recent flare-up of heavy fighting in the east has revived decades-old animosities between Kinshasa and Kigali, with the DR Congo blaming neighboring Rwanda for a resurgence of a militia called M23