Fighters trying to install Ivory Coast's democratically elected president descended Thursday on its largest city and seat of power, poised for a final push to unseat the entrenched ruler.
Forces backing Alassane Ouattara have overrun nearly 80 percent of the country as soldiers fled and towns fell in quick succession.
The regular army put up almost no resistance during the four-day offensive, including in the ruler's hometown, where fighters broke into Laurent Gbagbo's compound and slept in his bed.
But they may face fierce resistance on the peninsula where the presidential palace is located, surrounded on all sides by a natural moat -- Abidjan's glassy lagoon.
Gunfire could be heard throughout the day, along with the concussive boom of heavy artillery. Reporters saw soldiers in camouflage race across the waterside highway in pickup trucks mounted with machine guns.
As his forces amassed on the outskirts of Abidjan, Ouattara made a final appeal to Gbagbo to step down and called on the rest of the army to defect.
"[My fighters] have come to restore democracy and ensure respect of the vote by the people Today they are at the doorstep of Abidjan," Ouattara said in an address broadcast on his private TV station.
By mid-afternoon, as many as 50,000 soldiers, police and gendarmes had abandoned Gbagbo, according to the head of the United Nations mission, Choi Young-jin.
"Only the Republican Guard and his special forces have remained loyal," guarding the palace and residence, he told France-Info.
Ouattara was declared the winner of last November's presidential election by the country's election commission in results verified by international observers. But after a decade in power, Gbagbo refused to accept his loss. He has used the military to attack pro-Ouattara areas with heavy artillery and is accused of arming citizen militias and recruiting foreign mercenaries to defend his grip on power.
Up to 1 million people have fled the fighting, and at least 490 people have been killed since the election, most of them supporters of Ouattara.