Rwandan-backed M23 rebels in Democratic Republic of Congo are seeking to advance south towards Bukavu, the capital of South Kivu province, in an attempt to expand their area of control in the country's east after capturing the city of Goma.

Fighting between Rwanda-backed rebels and the Congolese army continued for a second day in Goma on Tuesday amid calls by African leaders for an immediate ceasefire.

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.