M23 rebels claim they now control the Congolese city of Goma—an act Congo's government described as a 'declaration of war.'

The U.N. said the rebels were supported by at least some regular Rwandan troops, in the worst escalation of a long-running conflict for more than a decade.

Rwandan-backed M23 rebels marched into the centre of Goma, the largest city in the eastern Democratic Republic of Congo.