MR Laurent Kabila arrived in Kinshasa after dark yesterday and immediately moved into the river-side residence previously occupied by Zaire's prime ministers.
Looting by residents after Mr Kabila's forces walked into the city on Saturday ruled out any option of his moving into one of the residences previously occupied by ousted president Mobutu Sese Seko.
Tens of thousands of Kinshasa residents earlier besieged the capital's airport road hoping to catch a first glimpse of the self-proclaimed president of what shall now be known as the Democratic Republic of Congo. Mr Kabila flew in from his southern stronghold of Lubumbashi.
The new leader had been expected to announce his transitional government yesterday. State radio, renamed Voice of Congo, said members of President Kabila's alliance were "in consultation with political personalities, notably Etienne Tshisekedi", the most prominent opposition leader under the toppled regime of President Mobutu Sese Seko.
One newspaper, Le Potentiel predicted that Mr Tshisekedi would be prime minister for the transition to a new constitution and, ultimately, full-scale elections.
The ailing former president, Mr Mobutu, prolonged his stay in the West African state of Togo on health grounds yesterday after his flight into exile left him "very, very weak", a government source said.
The rebel alliance's finance adviser, Mr Mawampanga Mwana Nanga, told reporters it would keep to its promise to hold elections within one year.
The United States and South Africa have led appeals to the alliance to form a broad-based government in the wake of their victory.
A US embassy employee in Kinshasa and his driver were killed in an ambush on Monday evening by armed men who were apparently trying to steal their car, US officials said.
The State Department spokesman, Mr Nicholas Burns, said the incident "appears to have been a random act of violence not directed against the US". Washington, is advising some 3,00 US nationals in the Democratic Republic of Congo to remain in their homes, and has no immediate evacuation plans, Mr Burns said.
Two French businessmen were also reported to have been killed yesterday, by men in uniform who intercepted their vehicle in the Limete district of Kinshasa.
News of the killings of the French men caused concern among remaining members of the French community in Kinshasa, where score-settling between supporters and adversaries of President Mobutu's regime have left dozens of people dead since the city fell over the weekend.
. In Paris, the international medical charity Medecins Sans Frontieres (MSF) yesterday accused the rulers of the new Democratic Republic of Congo of planning to exterminate all Rwandan Hutu refugees remaining in the country.
MSF said in a report released to the media that Hutu refugees in what was Zaire were being killed or starved and the assistance of relief groups was being systematically obstructed.
"To a large extent, this appears to be the result of a deliberate strategy by the AFDL [rebel alliance] aimed at the elimination of all remaining Rwandan refugees, including women and children," it said.
The alliance has denied it is following a policy of exterminating the Hutu refugees and accuses the United Nations and other agencies of deliberately failing to repatriate them from the east of the country.
The French Foreign Ministry, commenting on the MSF report, said those who committed the "atrocities" must be detained and prosecuted.
The French ministry's spokesman, Mr Jacques Rummelhardt, said the plight of refugees confirmed that France had been right in urging a multinational force to protect relief convoys.
The force was approved by the United Nations despite US reluctance but was later dropped after many refugees returned home to Rwanda.
MSF said that 900,000 refugees had returned home among more than 1.2 million Hutus who had fled from Rwanda in 1994 to escape reprisal for the genocide of up to 800,000 Tutsis and moderate Hutus. But an estimated 340,000 Rwandan refugees remained behind and 190,000 of them could not be located.
Their situation had been deteriorating since Kabila forces of attacked camps last October housing Hutus who had fled Rwanda after the genocide of Tutu- there.