(Reuters) -Chaotic scenes unfolded in the eastern Congo city of Bukavu on Saturday after M23 rebels reached its outskirts, while Congo's prime minister declined to comment on a threat by Uganda's army chief that raised fears of a spiral into a wider regional war.

M23’s advances highlight Rwanda’s role in the Democratic Republic of Congo, and the risk of an escalating regionalised conflict.

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