Rebel ministers in the Democratic Republic of the Congo have refused to swear an oath of loyalty to President Joseph Kabila, casting new doubts on the peace process.
Four vice-presidents were inaugurated on Thursdays
They accuse him of trying to extend his powers under the power-sharing government, which is supposed to end a war which has raged for almost five years, killing an estimated three million people.
Outside the national assembly building in the capital, Kinshasa, there is a lively show of singers and dancers but the rebel ministers refuse to leave their hotel rooms.
The rebels say Mr Kabila is head of the republic, not the government in the transitional authority.
The BBC's Ishbel Matheson in the capital, Kinshasa, says it may seem like a trivial complaint but the jockeying for political power is under way.
This row comes less than 24 hours after the inauguration of four new vice-presidents, including two rebels, raised hopes of an end to Africa's bloodiest war.
An official with the rebel RCD, Crispin Kabasele-Tshimanga, said that the ministers "did not want to consecrate a new dictatorship" or "personality cult" by swearing loyalty to Mr Kabila.
Other ministers in the new government took their oath of office on Tuesday but the RCD ministers delayed their arrival in Kinshasa in a row over how many bodyguards they would be allowed to take to the capital.
On Thursday, Azarias Ruberwa, RCD leader and new vice-president, said: "Our arrival marks the effective start of the transition."
"We have already announced the end of the war, now it's a reality."
The new government is supposed to organise the first multi-party elections since DR Congo's independence in 1960.
Even before this latest set-back, analysts said that unifying a country four times the size of France, across which there are few linking roads or railways, will be a huge task which could take many generations.