United Nations personnel, including military observers, pulled out en masse from Sierra Leone's rebel-besieged capital, Freetown, yesterday, witnesses said.
Television crews filmed UN staff boarding aircraft and helicopters at Lungi International Airport, which is across an estuary from Freetown.
The UN special envoy, Mr Francis Okello, confirmed they were leaving for Conakry, Guinea.
The UN Security Council yesterday condemned the entry of Sierra Leone rebels into the capital.
Most military personnel of the United Nations Observer Mission in Sierra Leone returned only on Sunday after pulling out to Guinea due to fighting last week.
It was not clear if observers based in the interior of the west African country had also assembled at Lungi.
A spokesman for the UN refugee agency, UNHCR, said seven motorised boats had arrived in Conakry yesterday carrying about 120 people fleeing from Freetown.
Asked about the state of fighting between rebels and Nigerian-led west African troops in Freetown, the UN observer, Col Andre Bobylev, said: "It's difficult to say. It's war."
Sierra Leone's envoy to Nigeria, High Commissioner Joseph Blell, was yesterday in the Nigerian capital, Abuja, to hold consultations with senior Nigerian officials.
Mr Blell said he hoped to meet defence and government officials today to discuss the situation. The official said the details of the situation in Sierra Leone were "scanty" and "confused", but he hoped to discuss the possibilities for action with the Nigerian officials.
Reports from Sierra Leone said that the Nigerian High Commission in Freetown had been burned down by the rebels opposed to the President, Mr Ahmed Tejan Kabbah. Nigeria has backed Mr Kabbah against the rebels.
In Abidjan, the World Food Programme expressed concern yesterday over food supplies in the Sierra Leonean capital.
The WFP feeds some 63,000 residents each day, according to the agency's spokesman in Abidjan.
"The situation is all the more critical now that food produce can only arrive in Freetown along one main road, that which the rebellion used to enter the city," the spokesman said.
"According to the latest information, food stocks were limited in Freetown, and most residents in the capital were surprised by the rebels' arrival and therefore didn't have time to prepare themselves," he said.
Britons caught up in the fighting were yesterday being warned by radio to get out or keep their heads down.
The Foreign Office was using the BBC World Service to broadcast appeals to the 50 or so expatriates remaining in the capital, Freetown, as rebel fighters rampaged through the streets.
Terrified residents huddled indoors as the government warned that anyone seen in the streets would be regarded as a rebel and shot.
The troubled west African state embroiled the Foreign Office in scandal after it emerged that British mercenaries were aiding the ousted President, Mr Kabbah, using British arms supplied in breach of a UN embargo.
Although ministers were cleared of any wrongdoing by a report commissioned by the Foreign Office, a committee of MPs is continuing to investigate the affair and is due to publish its report this month.