An unprecedented level of violence in the Central African Republic capital has left 30 dead in three days, the Red Cross says.
The violence occurred as French troops converged on a rebel-held northern town.
French military aircraft hovered over the strategic town of Sibut, 180 kilometres north of the capital Bangui, which was seized by ex-Seleka rebels on Thursday, prompting African troops and hundreds of frightened residents to flee.
"A military operation is happening in Sibut," a French communication officer told AFP on Friday, while a defence official in Paris confirmed the presence of the aircraft since Friday afternoon.
Newly installed interim president Catherine Samba Panza slammed the rebel efforts, saying they aimed to destabilise her mandate.
"At the time when the government is calling for togetherness, tolerance and national reconciliation, some of our countrymen are taking upon themselves the heavy responsibility of dividing the country," she said.
No Central African citizen "worthy of the name" would allow such "anti-patriotic, irresponsible and dangerous" actions, she added, vowing not to cede "an inch of our ground."
The installation of a new government in the strife-torn nation has failed to stem inter-religious violence between the mostly Muslim Seleka and Christian militia groups.
Tensions remain high in Bangui, where Red Cross officials said they had collected 30 bodies in the past three days after fighting which also left 60 people wounded.
The head of the International Committee of the Red Cross delegation Georgios Georgantas said he was very concerned by an unprecedented level of violence.
The poor, landlocked country descended into chaos 10 months ago after Seleka overthrew the government and installed one of its leaders, Michel Djotodia, as the country's first Muslim president.
His Seleka fighters began targeting people from the Christian majority, prompting the emergence of self-defence groups who launched revenge attacks on Muslims amid reports of murder, mutilation, rape and looting by both sides.
By the time Djotodia was effectively ousted by regional leaders on January 10 for his failure to end the spiralling bloodshed, about a million people were displaced out of a population of 4.6 million.
Georgantas urged the authorities and some 7000 French and African troops based near Bangui Airport to "take up their responsibilities" and keep the peace in a city abandoned by hundreds of thousands of residents.
The foreign soldiers were patrolling districts of the capital, where French troops this week warned looters that they would open fire if they failed to disperse.
In contrast the interior of the country is a lawless zone ruled by warlords, with few or no foreign troops present.
