Rwanda-backed rebels claimed on Monday they captured eastern Congo’s strategic city of Goma, the hub of a region containing trillions of dollars in mineral wealth that remains largely untapped.

The Rwandan-backed M23 rebels have released captured Romanian mercenaries who were fighting with the Congolese army. As they passed a border, they were chastised by Willy Ngoma, who tapped them mockingly one by one.

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