Several foreign ambassadors in the DRC have sought shelter in the house of an opposition leader after heavy shooting, BBC
They include the UK envoy and the head of the UN mission, a UN official said.
He said the UN, which has the world's largest peacekeeping force in DR Congo, has sent armoured vehicles to the area.
The gunfire follows Sunday's clashes between forces loyal to President Joseph Kabila and Jean-Pierre Bemba, rivals in October's election run-off.
UN spokesman Jean-Tobie Okala said the situation was confused, but confirmed that the envoys had sought refuge in Mr Bemba's residence in the city centre.
The ambassadors from the permanent five members of the UN Security Council - the UK, France, Russia, the US and China - were due to have been meeting Congolese politicians nearby although it is not yet clear which of them is trapped there.