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

The UN human rights chief has accused Rwanda-backed M23 rebels of committing atrocities, including child executions, after they took control of a second major city in eastern Congo. The ongoing conflict has resulted in significant casualties and displacement,

The European Parliament, in a strong resolution last week, slammed the inaction of European Union executives on the eastern Democratic Republic of Congo, where the Rwanda-backed M23 armed group is committing grave violations of the laws of war.