Congo has severed all diplomatic ties with Rwanda and South Africa said on Saturday that nine of its peacekeepers had been killed amid a surge in fighting with Rwanda-backed rebels in mineral-rich eastern Congo.

Rwanda-backed M23 rebels in the Democratic Republic of Congo have taken over the key eastern trading town of Minova, according to various sources. The fall of the city puts the rebels within 40km (25 miles) of provincial capital, Goma, which lies close to the border with Rwanda.

The M23 armed group has seized further territory in the east of the Democratic Republic of Congo and on Thursday was continuing to tighten its grip on provincial capital Goma, which is almost surrounded by fighting.

Fighting has escalated sharply in recent weeks in eastern Congo, where rebels have seized key towns and are closing in on the city of Goma, the government’s last stronghold in the North Kivu province,