Rwanda-backed rebels captured large parts of eastern Congo’s largest city including its airport, the United Nations said, as Rwanda's president on Wednesday joined calls for a ceasefire in the decadeslong conflict.

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.