Rwanda denies sending troops into neighbouring Democratic Republic of Congo, where U.N. investigators said in December thousands of Rwandan soldiers had been deployed in support of the M23 rebel group. The rebels took control of the city of Goma in the volatile, mineral-rich east on Tuesday.

Rwandan-backed M23 rebels asserted their control over east Congo's largest city Goma on Thursday by calling on residents to resume normal life, even as the group clashed with Congolese troops as they tried to take more territory.

Congolese President Félix Tshisekedi has vowed to restore government authority in the east, where Rwanda-backed M23 rebels have seized control of the city of Goma and are reportedly advancing south to take more territory.