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.

Residents of Goma reported gunfire and shelling after rebels overran Congolese troops. U.N. officials estimated that more than one million displaced people were now inside the city.

Rwandan President Paul Kagame blasted criticism of his country's role in eastern Democratic Republic of Congo where rebels his government backs have seized its largest city, saying Kigali is prepared for "confrontation" if necessary.