Officials from the largest rebel group in the Democratic Republic of Congo have failed to fly to the capital, Kinshasa, to take up their seats in a new power-sharing government.
The RCD is worried about its security in Kinshasa
The plane provided for them by the UN mission in Congo (Monuc) did not have enough space for the entourage, because of the large number of security guards the rebels wanted to bring with them.
The swearing-in ceremony, which was due to take place on Monday, has been postponed until after the four vice-presidents are sworn in on Thursday this week.
The transitional government was agreed last December in order to end four years of conflict involving six other African countries.
Each of the 12 delegates from the Rwanda-backed RCD-Goma group wanted to take 15 bodyguards to Kinshasa, which they say was part of a security agreement.
However Monuc only supplied a 17-seater aircraft to transport them from their headquarters in the eastern city of Goma.
"Any action that aims to make the RCD ministers leave without their personal guard will be considered a blatant violation of the accords," said rebel spokesman, Jean-Pierre Lola-Kisanga.
RCD-Goma, the MLC rebels, the civilian opposition and the government of President Joseph Kabila will share posts in the transitional authority, which is due to organise the country's first multiparty elections since independence from Belgium in 1960.
Most of DR Congo has been relatively peaceful in recent months, except around the north-eastern town of Bunia, where thousands have been killed in fighting between ethnic militias following a pull-out of Ugandan troops.
A French-led intervention force has been deployed to Bunia.
Last week, they killed three militia fighters.
More than two million people have died as a result of the conflict, either through disease and hunger or directly in the fighting.