If the rebels capture the capital of South Kivu province, it would represent an unprecedented expansion of territory under their control Rwandan-backed M23 rebels appeared on Friday to be closing in on eastern Democratic Republic of Congo's second-largest city,

The Democratic Republic of Congo is in turmoil - fighters from the notorious M23 rebel group have been surging through the country's east, battling the national army and capturing key places as they go.

Rwandan-backed M23 rebels who in late January captured Goma, the biggest city in eastern Congo, have since been advancing around one of Africa's great lakes, Lake Kivu, towards the second-biggest city in the area,