Forces opposed to Ivory Coast leader Laurent Gbagbo have launched a final assault on the presidential residence where he is holed up.
Mr Gbagbo has been in negotiations with the UN over the terms of his departure, after being besieged by troops loyal to his rival Alassane Ouattara.
A French government source said gunfire had erupted at Mr Gbagbo’s residence in Abidjan.
Mr Gbagbo insists he won last November’s run-off vote.
But the Ivorian election commission found that Mr Ouattara was the winner – a result certified by the UN.
Mr Gbagbo and his family are believed to be sheltering in the bunker of the presidential residence, which was controlled by his troops.
Two days of heavy fighting stopped late on Tuesday and negotiations with Mr Gbagbo carried on throughout the night.
But by Wednesday morning it appeared the patience of pro-Ouattara forces had run out.
“We are going to get Laurent Gbagbo out of his hole and hand him over to the president of the Republic,” said Sidiki Konate, spokesman of Mr Ouattara’s prime minister, Guillaume Soro.
‘In the building’
Affousy Bamba, a spokeswoman for troops backing Mr Ouattara, told Reuters news agency: “Yes they [Ouattara forces] are in the process of entering the residence to seize Gbagbo.
“They have not taken him yet, but they are in the process, they are in the building.”
Mr Gbagbo had earlier denied he was surrendering, saying he was only negotiating a truce.
“I won the election and I’m not negotiating my departure,” he said.
“I find it absolutely incredible that the entire world is playing this… game of poker.”
The BBC’s John James outside Abidjan says with most of Mr Gbagbo’s forces having laid down their arms it is not clear how much resistance pro-Ouattara forces will face.
It feels like it is the “endgame” for Mr Gbagbo, he says.
French Armed forces chief Adm Edouard Guillaud told Europe 1 radio that Mr Gbagbo had twice been on the point of stepping down – on 1 April and 4 April – before pulling back.
Asked if Mr Gbagbo had any choice other than surrender, he said: “No, to my mind he has no other choice.”
On Monday pro-Ouattara fighters launched a “final assault” and UN and French helicopters attacked Mr Gbagbo’s military installations in Abidjan saying it was in order to protect civilians.
Following Tuesday’s ceasefire, the city passed a largely quiet night, apart from shootings blamed on gangs, but its population of four million remained indoors.
Civilians told the BBC they were very scared. Small groups have been walking out of the city with their hands raised in the air.
Last November’s election was intended to reunite Ivory Coast which split in two following a northern rebellion in 2002.
The electoral commission pronounced Mr Ouattara the victor, but Ivory Coast’s Constitutional Council said Mr Gbagbo had won.
The US, the UN and the EU recognised Mr Ouattara as the winner, but both candidates had themselves sworn in as president and a stand-off ensued.
Skirmishes and battles between the rival forces have since taken place across Ivory Coast culminating in Mr Ouattara’s troops sweeping into Abidjan at the end of March.