The M23 rebels have been trying to make inroads in mineral-rich eastern DR Congo, along the border with Rwanda, in a decades-long conflict that has sparked one of the world's largest humanitarian crises.

The M23 rebel group's aggressive advance into the mineral-rich east of the Democratic Republic of Congo has displaced thousands, threatening areas like Goma. The rebel force has gained control of key mining territories,

Congolese helicopter gunships swooped low over the plains to fire volleys of rockets and troops trucked towards the front line to halt Rwanda-backed fighters advancing on DR Congo's eastern provincial capital after capturing a string of towns.