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

Rwanda's ally Uganda, unhappy about another rebel group in DR Congo that threatens its security, has also been accused of helping the M23 - with its officers also spotted at Tchanzu. The UN experts say Uganda has also supplied weapons, hosted rebel leaders and allowed cross-border movements of M23 fighters - accusations Kampala denies.