(Reuters) -Rwandan-backed M23 rebels entered eastern Democratic Republic of Congo's second-largest city Bukavu on Friday, a rebel leader told Reuters, as residents reported seeing the militants in the streets of a northern district.

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

The Democratic Republic of Congo has been mired in conflict for years. As fresh fighting surges in the east, the roots of today’s violence can be traced back to old problems.