U.N. peacekeepers moved to secure the Abidjan airport by sending armed elements and additional personnel there, according to a U.N. peacekeeping official in New York who was not authorized to speak publicly.
Patrick Achi, a spokesman for Ouattara, said the fighters — largely drawn from a northern rebel group that launched a 2002 rebellion against Gbagbo — had breached the city limit overnight.
It was unclear whether Gbagbo was inside the presidential mansion. The defiant leader has not been seen in public since the offensive began five days ago.
"We don't know where he is," a senior diplomat told The Associated Press. He asked not to be named because he is not authorized to speak to the press.
A Swedish woman working for the United Nations was killed by a stray bullet during fighting in Abidjan on Thursday night, the Foreign Ministry in Stockholm confirmed. Some 500 foreigners sought refuge at a French military base, Col. Thierry Burkhard told the AP.
The chairperson of the commission of the African Union, Jean Ping, urged Gbagbo to immediately hand over power to Ouattara "in order to shorten the suffering of the Ivorians," the AU said in a statement from Addis Ababa, Ethiopia.
Gbagbo lost last November's presidential election according to his country's election commission and international observers, but has stubbornly refused to step down. Sanctions imposed on him and his inner circle failed to dislodge him.
The armed offensive is the most severe threat that he has faced, and analysts say they expect Gbagbo's regime to fall within days. "It's over — except for the shooting," said the diplomat.
Gbagbo was defeated in elections this past November by Alassane Dramane Ouattara, but Gbagbo refused to step down, setting up the current conflict.