The M23 militia is ruling over a vast stretch of territory in the eastern part of the Democratic Republic of Congo, threatening the sovereignty of the biggest country in sub-Saharan Africa.

(Reuters) -Rwanda-backed M23 rebels pressed deeper into Congolese territory a day after Congo and Rwanda's presidents called for an immediate ceasefire, entering the outskirts of the town of Walikale late on Wednesday,

Rwanda has denied supporting M23. It says its military has been acting in self defence against Congo’s army and a militia founded by some of the perpetrators of the 1994 Rwandan genocide.

The Rwanda-backed rebels who captured key areas of Congo’s mineral-rich east say they have withdrawn from planned peace talks with the country’s government in Angola.