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.

BUKAVU, Congo — Rwanda-backed rebels tightened their grip on Bukavu on Monday, a day after seizing the second major city in eastern Congo whose residents appeared resigned to their fate under the new rulers.

Rwanda-backed rebels appeared to be heading toward a third major city in eastern Congo, residents said Tuesday, as international pressure rose over the M23's expansion in a mineral-rich region that’s critical for global technology.

M23 rebels in the Democratic Republic of Congo have captured the eastern city of Bukavu with the backing of Rwandan forces, the second major city in the mineral-rich Kivu region to fall in three weeks.