The United States, France and the UN secretary-general have called on Cote d'Ivoire's incumbent president to step down as forces loyal to his internationally recognised rival fight fierce battles to force him out of power.
Mark Toner, a spokesman for the US state department, said on Friday that time for Laurent Gbagbo was "drawing nigh", adding: "We would urge Mr Gbabgo to read the writing on the wall and to step down now."
France, which still has ties with its former colony and follows its affairs closely, called on Gbagbo in a statement to "step down immediately, stop the violence and cede power peacefully to President Alassane Ouattara".
The statement followed an afternoon meeting on Friday between Nicolas Sarkozy, the French president, foreign affairs and defence ministers, and other officials to discuss the situation in the West African country.
Saying there has been too much bloodshed in Cote d'Ivoire, Ban Ki-moon, the UN chief, renewed his call on Gbagbo to step down to avoid further violence, and transfer power immediately to Ouattara.
"I once again urge all parties – let me repeat all parties – to exercise restraint," Ban told reporters in the Kenyan capital, Nairobi, where he is on an official visit.
A journalist in Abidjan tells Al Jazeera that Gbagbo's options are limited
"I would remind all those who commit serious violations of international humanitarian and human rights laws that they will be held accountable."
The UN estimates at least 400 people have been killed in the violence related to last November's disputed election which was won by Ouattara, but Gbagbo has refused to step down forcing his rival - who has been endorsed by the UN, ECOWAS and the African Union - to set up a parallel government.
A spokesman for Gbagbo swiftly reacted to calls for his boss to quit saying the president will continue in power.
Heavy fighting raged on Friday in the neighbourhoods close to the presidential palace as well as near Gbagbo's home and the state TV broadcaster, as armed forces backing Ouattara tried to install him in power.
French officials said Gbagbo was still in the country despite attacks by rival forces, and is probably in the presidential residence.
"We are practically certain that he is in Abidjan in his residence," one French official who asked not to be named told the AFP news agency.
Seyi Rhodes, a journalist in the commercial capital Abidjan, told Al Jazeera Gbagbo's whereabouts were "very vague" and that his words have only been heard from his aides.
"His spokespeople are saying he is still here in Abidjan. He hasn't been seen for a very long time. Members of his government have defected or many of them are trying to leave," Rhodes said.
"There are rumours that some of them are stuck at the airport trying to get out of the country.
"It would be an ideal time for him to make an announcement to say that he is still here, but so far we have only heard his words from his spokesperson."
The latest fighting claimed a Swedish national working with the UN mission which has 8,000 peacekeepers in the country, the UN and a security source said.
The security source said Zahra Abidi was on the balcony of a friend's house while shooting was going on when a stray bullet hit her.
Frenchman found dead
A French language teacher was also found dead with a gunshot wound in a hotel room in the city of Yamoussoukro, the country's official capital.
A foreign ministry official said the embassy was investigating the circumstances surrounding the death together with local authorities and the victim's family.
The official spoke on condition of anonymity citing ministry policy.
It was unclear whether the teacher was targeted because of his nationality, whether the death is connected to the ongoing violence, or whether it was a result of an unconnected crime.
The escalating violence has seen French forces deploying in some parts of Abidjan, local residents said.
One source said soldiers from the 1,000-strong French force had been deployed in Zone 4, in the south of the city.
A Western military source said others were sent to rescue some French nationals being attacked in the Deux Plateaux neighbourhood by youth supporters of Gbagbo. France's armed forces declined to immediately comment.
On the peninsula where the presidential palace is situated, witnesses told the Reuters news agency that buildings were shaking with each explosion in the early hours of Friday.
Patrick Achi, a spokesman for Ouattara, who ordered the country's borders and the main airport closed to prevent Gbagbo and his allies from fleeing, said the fighters had breached the city limit overnight and were waging battles at the palace and the residence.
Achi said the forces, who are former rebels that fought in the 2002-3 civil war that left Ivory Coast divided, had seized Radio Television Ivoirienne, or RTI, the state broadcaster late on Thursday.
With the television station that Gbagbo has used as a mouthpiece cut off, no news emerged from his camp, which has been hit by a number of high-level defections in the military.
But a Paris-based adviser said his surrender was "out of the question".
"He has no intention of resigning," said Toussaint Alain.
As his forces massed on the outskirts of Abidjan, Ouattara on Thursday made a final appeal to Gbagbo to step down, and called on the rest of the army to defect.
"I call on you to serve your country [...] It is time to join your brothers in the Republican Forces," Ouattara said in a statement aimed at encouraging members of the security forces still loyal to Gbagbo to defect.
In the biggest blow yet to Gbagbo's grip on power, the South African government said General Phillippe Mangou, Gbagbo's army chief of staff, had defected and sought refuge at its ambassador's residence in Abidjan.
The worsening security situation has led to a warning from Amnesty International that civilians in Abidjan are at immediate risk of "massive human rights violations".
"Abidjan is on the brink of a human rights catastrophe and total chaos," Salvatore Sagues, Amnesty's researcher on West Africa, said.
"... The parties to the conflict must immediately stop targeting the civilian population," Sagues said, adding: "The international community must take immediate steps to protect the civilian population."