(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.

Trucks and cars full of Congolese soldiers carrying their weapons could be seen circulating in Bukavu, South Kivu province on Friday. It came as Rwanda-backed rebels in eastern Congo claimed that they have seized a second airport in the region following a days-long advance.