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.

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.

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.

In Bukavu, a city in eastern Democratic Republic of Congo, at least 11 people have been killed in vigilante attacks following the withdrawal of the army. M23 rebels are trying to impose order, retraining police under their control,

Gunfire disrupted a rally by M23 leader Corneille Nangaa in Bukavu, escalating fears of regional conflict between the Democratic Republic of Congo and its neighbors. M23 claims territorial control and is attempting to establish order,

Rwanda-backed rebels who captured eastern Congo’s major city of Goma have targeted relatives of fleeing Congolese soldiers. That's according to the soldier's families.

The explosives that hit a huge crowd of people who had turned up in their thousands for an AFC/M23 rally in Bukavu, on February 27, caused the death of at least 11 people and injured 65, of whom six are in critical condition, according to group's leader.

U.K. authorities are punishing Rwanda over its support of the rebels who now control two major cities in eastern Congo.