A rebel group has said it has advanced into Bukavu, the second largest city in the eastern Democratic Republic of Congo (DRC), with residents reporting looting and fighters in the streets.

(Reuters) -Chaotic scenes unfolded in the eastern Congo city of Bukavu on Saturday after Rwanda-backed M23 rebels reached its outskirts, while a threat by Uganda's army chief to attack a Congolese town raised fears of the conflict flaring into a wider regional war.

The Rwandan-backed rebels' entry into Bukavu follows their capture of Goma, defying international calls for a ceasefire.

If the rebels capture the capital of South Kivu province, it would represent an unprecedented expansion of territory under their control Rwandan-backed M23 rebels appeared on Friday to be closing in on eastern Democratic Republic of Congo's second-largest city,