The United Nations meanwhile said the battle for the key city of Goma, which the M23 and Rwandan troops seized last week, had left at least 2,900 people dead - far higher than the previous death toll of 900.

The M23 and Rwandan forces on Wednesday launched a new offensive in eastern Democratic Republic of Congo, seizing a mining town in South Kivu province, as they resumed their advance

Nearly 3,000 people were killed over the last week as rebels captured a key city in one of the deadliest battles in the Central African country in decades.

Rebels in eastern Congo's largest city, Goma, began a ceasefire on Tuesday and people rushed to bury some 2,000 victims of last week's battles for the city as they feared the spread of disease.

A rebel group that claimed to have captured the city of Goma in the eastern Democratic Republic of Congo last week has called for an immediate humanitarian ceasefire, after fighting with the Congolese military has left hundreds of people dead.