Residents say Rwanda-backed rebels appear to be heading toward a third major city in eastern Congo. International pressure rose Tuesday over the M23’s expansion in the mineral-rich region that’s critical for global technology.

Rwandan-backed rebels have entered Bukavu, a major city in the mineral-rich east of the Democratic Republic of Congo.

M23 rebels backed by Rwanda took the city of Goma in a bloody battle. This weekend, the group entered the gold-trading center of Bukavu in eastern Congo after government soldiers fled.