United Nations Secretary General Ban Ki-moon on Monday expressed "extreme concern" over increasing attacks on UN peacekeepers and civilians in the Democratic Republic of Congo's northern provinces.

Ban cited the situation in North Kivu, Rumangabo and Goma, where a local armed group called the National Congress for the Defence of People attacked UN peacekeepers and government military troops, in violation of a ceasefire.

Ban called on all parties to respect the ceasefire and "pursue ... efforts to resolve peacefully the issues that have thus far hindered progress in the Nairobi and Goma processes."

The government in Kinshasa and rebel groups have signed ceasefire agreements to end the conflict. But fighting has continued in border regions, particularly in northern Congo.

Ban also appointed Brigadier General Ishmeet Ben Quartey of Ghana to serve as acting commander of the UN mission in Congo after Lieutenant General Vicente Diaz de Villegas stepped down for personal reasons after just a short period in the job.