Forces loyal to Ivory Coast presidential claimant Alassane Ouattara launched a heavy attack on the bunker where Laurent Gbagbo is surrounded but appeared to have been repelled, a Western military source said.
Fighting raged for a third straight day in the economic capital Abidjan as Ouattara's forces tried to unseat Mr Gbagbo, who has refused to cede power after losing a November election to Mr Ouattara, according to UN-certified results.
The source, who lives near Mr Gbagbo's heavily defended residence in Abidjan, said fighting had died down in the afternoon and Mr Ouattara's forces had regrouped.
"As I understand it, they tried to take Gbagbo residence this morning. The assault failed," said the source, speaking on condition of anonymity.
"They could not break through the resistance from all the heavy weapons still hidden around Gbagbo's residence. They pulled back to rethink and replan."
A spokeswoman for Ouattara denied that his forces had retreated but could not provide any details about the ongoing assault and could not say whether fighting continued.
Residents had earlier reported gunfire from heavy weapons around the residence, which is guarded by youth militias and Gbagbo's presidential guard.
Earlier, it emerged South Africa, Togo and Angola are possible safe havens for Ivory Coast's besieged Laurent Gbagbo should he negotiate an exit from his West African country.
"South Africa has offered several times before and Togo is now indicating to us that it could be willing to take him in," a senior African Union official told Reuters.
"Togo is not a great option, though, as there will obviously be fears that he could cause problems and spoil peace from there - it's so close to Ivory Coast. I'm betting strongly on South Africa," said the official.
Two other diplomats in Addis Ababa also said today they had heard South Africa and Togo had made asylum offers.
The former colonial power, France has taken a lead role in talks to persuade Mr Gbagbo to hand over to rival Mr Ouattara and end a four-month standoff over a November election that UN-certified results say Mr Ouattara won.
Another diplomat at the AU in Addis Ababa said Angola was a strong possibility. "Angola has always been pro-Gbagbo," one Western diplomat told Reuters. "I think there's a good likelihood of Angola taking him in if there's a settlement. You only have to look at their history."
The United Nations said in March it was investigating suspected arms transfers to Ivory Coast in breach of an embargo, including a cargo delivery from Angola.
There were also regular reports in 2002 that Angola supplied arms including armoured vehicles to Ivory Coast when rebels tried to oust Mr Gbagbo from the presidency.
Angola has denied that mercenaries from the country have fought for Mr Gbagbo.
Diplomats at the AU headquarters in Ethiopia said Uganda was an outside bet to shelter the Ivorian strongman. Long-serving President Yoweri Museveni earlier this year attacked the United Nations for recognising Mr Ouattara as the election winner.
Mr Museveni, who won a disputed presidential poll in February and faced possible opposition protests, said there should be an investigation into the Ivory Coast poll.
Reuters