Rebel forces have been seen in the center of Bukavu, the second largest city in the eastern Democratic Republic of Congo (DRC), on Sunday, residents told CNN, as the fighters push to expand their foothold in the mineral-rich region.

Rwandan-backed M23 rebels were seen in the centre of eastern Congo's second-largest city, Bukavu, on Sunday, said a local official, a security source and five eyewitnesses.

Rwanda-backed rebels have captured two major cities in Congo’s mineral-rich east after a major escalation in their yearslong fighting against Congolese forces