Rebels in the Central African Republic fighting to topple President Francois Bozize seized control of the capital Bangui on Sunday, with the whereabouts of their archfoe unknown.
Fighters in the Seleka rebel coalition launched an assault on the riverside capital 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 rebels are in control of the city even though there is still some sporadic gunfire," a source in the multinational central African force FOMAC told AFP.
Gunbattles had erupted around the presidential palace early Sunday after the rebels moved in to the city on Saturday, facing little resistance from the poorly-equipped and ill-trained army, but the whereabouts of Bozize are unknown.
"We have taken the presidential palace. Bozize was not there," one of the rebel commanders on the ground, Colonel Djouma Narkoyo, told AFP.
He said the rebels were planning to move on to the national radio station where Seleka leader Michel Djotodia would make an address.
"Today will be decisive," Narkoyo had said earlier. "We call on our brothers in FACA (the Central African army) to lay down their arms."
Bozize, who himself led a coup in the landlocked country in 2003, has not been seen since his return from a brief visit to South Africa on Friday.
There were no official statements from the government Sunday about the latest developments, although a high-ranking military source confirmed: "What is certain is that they (the rebels) have taken the city."
Heavy gunbattles erupted at about 0700 GMT, but later the shooting became more sporadic, an AFP correspondent said, causing panic among residents.
"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.
And he warned that if Seleka - a loose alliance of three rebel movements - captured Bangui, it would set up a new government.
The city was plunged into darkness on Saturday after rebels sabotaged a hydroelectric power plant in Boali, north of the capital, an official with the Enerca electricity company and residents said.
A spokesperson for Prime Minister Nicolas Tiangaye on Saturday had called on the rebels to accept talks to "avoid a bloodbath".
Tiangaye, an opposition figure, was only appointed as part of the peace deal brokered between the government and the rebels in January, an agreement that broke down last week.
Paris-based rebel spokesperson Eric Massi has said the rebel leadership was urging its forces on the ground to refrain from "looting or score-settling with the local population".
Former colonial power France on Saturday called for an emergency meeting of the UN Security Council to discuss the deteriorating situation, said Romain Nadal, a spokesman for the president's office.
France had not issued an evacuation order, but the estimated 1,250 French nationals in the country were advised to stay at home, said Nadal.
There were no immediate plans to send reinforcements to back up the 250 French troops in the country to protect them, he added.
The UN 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 in conflict.
Seleka first launched its offensive in the north of the country 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 national elections next year.
But that deal collapsed this month 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 where Bozize himself seized power in a 2003 coup.
The country has been plagued by coups and army mutinies since its independence from France in 1960.