At least 11 people were killed in attacks over the past day in the rebel-held Democratic Republic of Congo city of Bukavu as vigilante violence rises following the army's withdrawal, witnesses and a civil society activist said on Thursday.

The current fighting is the result of a decision by Congolese President Felix Tshisekedi to incite ethnic violence and to support groups that perpetrated the Rwanda genocide.

Since January, however, the rapid conquest and occupation of a huge area of the Democratic Republic of Congo by Rwanda and the M23 rebel group it supports has raised concerns that the principle may now be endangered.

Rwanda is asking Britain for a 50 million-pound payment over a cancelled asylum deal, a source close to the government in Kigali said on Tuesday, after London paused some bilateral aid to the African country over the war in Congo.

Explosions at a rally in Bukavu, Congo, resulted in 11 deaths and 65 injuries. The M23 rebels accuse President Tshisekedi of the violence, while the Congolese presidency blames a foreign army. Tangled accusations involve Rwanda and Burundi's involvement.