UN Secretary-General Ban Ki-moon has made a fresh plea for 3,000 more peacekeepers to be sent to the east of the Democratic Republic of Congo, BBC reported.
In New York, Mr Ban also called for a ceasefire so aid workers could urgently help "at least 100,000 refugees" cut off in rebel-held areas near Goma.
A 17,000-strong UN force in Congo has been unable to stop the fighting or halt the rebel advance.
The UN Security Council is considering the call for reinforcements.
The UN head of UN peacekeeping operations, Alain Le Roy, said there were currently only 10 UN soldiers for every 10,000 inhabitants in eastern DR Congo.