Rwanda-backed rebels were expanding their presence in eastern Congo after capturing Goma, the region's major city, the U.N. said Friday, also expressing concerns over executions it learned were carried out by the rebels in recent days following a major escalation of their yearslong rebellion.

The rebel leader whose fighters have captured Goma, the biggest city in eastern Democratic Republic of Congo, has vowed to continue their offensive all the way to the capital, Kinshasa. Corneille Nangaa, who heads an alliance of rebel groups that includes the M23, said their ultimate aim was to topple President Félix Tshisekedi's government.

Congo’s leader has called on young people to enlist in the army to help fight Rwanda-backed rebels attempting to seize more territory in the country’s conflict-battered east