The United Nations peacekeeping chief said Friday that the Mouvement du 23 mars (M23) rebel group is advancing on the South Kivu provincial capital of Bukavu, after seizing control of Goma in the mineral-rich eastern Democratic Republic of Congo (DRC, DR Congo) earlier this week. Meanwhile, UN agencies warn that the situation continues to deteriorate for civilians trapped by days of intense fighting in and around Goma, the capital of North Kivu province.