Rebels in the Central African Republic seized control of the capital Bangui on Sunday after a rapid assault, with President Francois Bozize reportedly fleeing the country.
Fighters in the Seleka rebel coalition launched an offensive on Bangui after the collapse of a two-month-old peace deal in the notoriously unstable former French colony -- ignoring a call for talks to avoid a "bloodbath".
The whereabouts of Bozize, who himself came to power through a coup in 2003, remained a mystery. He has not been seen since his return from a brief visit to South Africa on Friday.
A well-placed source told AFP he had "left the country in a helicopter", but did not disclose his destination.
Officials from the neighbouring Democratic Republic of Congo and Congo-Brazzaville said he was not on their soil, although it would be easy to cross the river Oubangui to reach the DRC.
After a morning of gunbattles centred around the presidential palace, witnesses reported widespread looting by armed men as anarchy reigned in the riverside capital in the wake of the seizure, with attacks on shops, houses and cars.
"The rebels are in control of the city even though there is still some sporadic gunfire," a source in multinational central African force FOMAC told AFP.
The fighting erupted after the rebels -- who first launched an offensive against the government late last year -- moved in to the city on Saturday, facing little resistance from the poorly equipped and ill-trained national army.
"We have taken the presidential palace. Bozize was not there," one of the rebel commanders on the ground, Colonel Djouma Narkoyo, told AFP.
Describing Sunday as a "decisive day", he said the rebels were planning to move on to the national radio station, where Seleka leader Michel Djotodia would make an address.
There were no official statements from the government about the latest developments, although a high-ranking military source confirmed: "What is certain is that they (the rebels) have taken the city."
"We heard gunfire everywhere in the city centre. It was chaos," said one witness. "Everyone started running in all directions."
Narkoyo had told AFP on Saturday the rebels were ready to meet with regional African leaders on the crisis in the mineral-rich but deeply poor country, but refused to negotiate with Bozize.
He had warned that if Seleka -- a loose alliance of three rebel movements -- captured Bangui, it would set up a new government.
Seleka spokesman Eric Massi said from Paris that the rebels controlled the capital and military camps and were deploying throughout the capital, "in order to launch security operations and prevent looting".
The city had been plunged into darkness on Saturday after rebels sabotaged a hydroelectric power plant in Boali, north of the capital, said residents and an official with the Enerca electricity company.
A spokesman for Prime Minister Nicolas Tiangaye on Saturday had called on the rebels to accept talks to "avoid a bloodbath".
Tiangaye, an opposition figure, was appointed as part of a peace deal brokered between the government and the rebels in January, an agreement that broke down last week.
Former colonial power France on Saturday called for an emergency meeting of the UN Security Council to discuss the deteriorating situation.
France had not issued an evacuation order, but the estimated 1,250 French nationals in the country were advised to stay at home, said Romain Nadal, a spokesman for the president's office.
There were no immediate plans to send reinforcements to back up the 250 French troops in the country, he added.
The Security Council on Friday voiced strong concern about the rebel advances "and their humanitarian consequences", amid reports of widespread summary executions, rapes, torture and the use of children.
Seleka first launched its offensive in the north on December 10, accusing Bozize of not abiding by the terms of previous peace agreements.
Facing little resistance from the army, they seized a string of towns, defying UN calls to stop before halting within striking distance of Bangui.
They reached a peace deal with the government in January under which Tiangaye became head of a national unity government that was to carry out reforms before elections next year.
But the deal collapsed after the rebels said their demands, which included the release of people they described as political prisoners, had not been met.
The international community has nervously watched the spike in tensions in the landlocked nation of 4.4 million people that has been plagued by coups and army mutinies since independence in 1960.