Congolese rebels have declared a ceasefire after four days of fighting that have precipitated “a humanitarian crisis of catastrophic dimensions” according to the United Nations.

As the UN Security Council pleaded for restraint, the forces of renegade Tutsi commander Laurent Nkunda on Wednesday tightened their noose around the eastern city of Goma and captured a significant Congolese army base. By the evening they had captured a stretch of territory along the Rwandan border and were advancing towards Goma, threatening to overwhelm UN peacekeepers who have their principal base there.