The bog covers an area the size of England and is thought to contain billions of tons of peat.
Insurgency that may have ties to Rwanda could be on the way back already.
Peace talks have repeatedly stalled since they started in December.
Army holding M23 fighters, including top comander, official says.
Group will seek to resolve grievances through "political means only."
Uganda protests as shells landing within its borders injure five.
But M23's setbacks don't spell end of violence in mineral-rich east Congo.
Congolese army attacked one of the last remaining strongholds of the M23 rebels.
More expected to flee as fighting intensifies near border.
The Congolese army colonel marched triumphantly into town, welcomed by cheering crowds waving palm leaves after his soldiers retook this base in their latest offensive to quash the M23 rebels.
