Fighting has escalated sharply in recent weeks in eastern Congo, where rebels have seized key towns and are closing in on the city of Goma, the government's last stronghold in the North Kivu province,

Laden with just the possessions they can carry, thousands of displaced people have reached the outskirts of the city of Goma in eastern Democratic Republic of Congo, fleeing a rapid M23 rebel advance that has taken more territory than ever before.

Advances being made by the M23 rebel group in the Democratic Republic of Congo are "heightening the threat of a regional war," according to U.N. Secretary General Antonio Guterres.