Rwanda-backed rebels have captured two key cities in Congo’s mineral-rich east in less than a month after a major escalation in their yearslong fighting against overstretched and weakened Congolese forces.

Nearly three thousand people have been killed in the city of Goma in the eastern Democratic Republic of Congo, according to the United Nations, after the provincial capital was captured by rebels following days of fierce fighting with the Congolese army.

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.