ABIDJAN, Ivory Coast (AP) -- Laurent Gbagbo's 10-year grip on the Ivory Coast seemed to be in its final hours Friday after fighters encircled both his residence and the presidential palace and battled to unseat the man who has refused to recognize his defeat in last year's election.

The Skanner News Video here

Even in the face of a rapid military advance that has swept across Ivory Coast, the world's largest cocoa producer, and arrived at his doorstep, Gbagbo rejected calls to step down.

His aides defiantly said they will never give in, even though nearly 80 percent of the country and now large swaths of its largest city are controlled by an armed group fighting to install the internationally recognized winner of the election, Alassane Ouattara.

"There is no question of ceding," said Gbagbo's presidential aide, Fred Anderson. "It's not up to the international community to impose our leader."

In the Cocody neighborhood where the presidential mansion is located, families slept in bathrooms and on the floor as successive blasts punctuated the all-night assault.

People living near the presidential palace a few miles to the west were awakened by a barrage of explosions, some so strong they made the walls of buildings tremble.

During the day, machine-gun fire could be heard at either end of the waterside highway leading to the palace. It is strategically located on a peninsula surrounded on all sides by a lagoon, and military vehicles mounted with rocket launchers sped by while Mi-24 helicopters circled.

Gbagbo delayed the November election by five years, canceling it every year only to promise, but fail, to hold it the next.

Ouattara's victory with 54 percent of the vote was recognized first by the country's electoral commission and then by the United Nations, which pored over thousands of tally sheets before certifying the results. He has been recognized by governments around the world, and leaders from U.S. President Barack Obama to French President Nicolas Sarkozy have made personal appeals to Gbagbo to step down.

"This turn of events is a direct consequence of the intransigence of the outgoing president, Mr. Laurent Gbagbo, who has repeatedly refused to heed calls for him to cede the reins of power in the country to the president-elect, Mr. Alassane Ouattara," said a statement Friday by the regional Economic Community of West African States.

Gbagbo, 65, has not been seen in public since the offensive began five days ago, but those in his inner circle say he is still in Abidjan and will fight until the end. It's unclear where he is holed up, with Ouattara's camp speculating he is in a bunker in the palace.

Reached by telephone, however, one of Gbagbo's closest associates, Foreign Minister Alcide Djeje, said he was at Gbagbo's side at the presidential residence in Cocody.

Cocody resident Yeo N'Dri said Friday that he could see a thick column of smoke rising from the area where the residence is located. Abidjan was at a standstill, with people barricaded indoors.

The few cars on the streets had their emergency lights flashing. Some drivers held their right hand on the wheel and their left hand pointed outside to signal that they aren't armed.

Ouattara ordered land and sea borders closed to seal all the exits in case Gbagbo attempts to flee, said Foreign Affairs Minister Jean-Marie Kakou-Gervais.

"His inner circle is trying to run, but they won't be able to," he said.

At least 1 million people have fled Abidjan and 494 have been killed during the four months of violence waged by Gbagbo's security forces. Early on, world leaders offered him amnesty and a golden parachute in return for leaving peacefully. The United Nations has said his regime will be investigated for possible crimes against humanity.

Members of Ouattara's administration said the battle would already be over if Ouattara had not given specific instructions to not harm Gbagbo.

"It is not our wish to kill him," Kakou-Gervais said. "We would like the Red Cross to be a witness. We invite them to be with us when we take him."

For most of the standoff, it was Gbagbo's security forces that committed abuses against civilians, according to visits to local morgues by The Associated Press, eyewitness reports by AP reporters and photographers, and interviews with Ivorians and human rights officials. Those reports bolstered Ouattara's international stature, and his supporters only recently started to arm themselves and fight back.

That could change now that Ouattara has accepted help from a northern-based rebel group, whose members make up the majority of the fighters now assaulting Abidjan.

U.N. Secretary-General Ban Ki-moon again called on Gbagbo to step down and transfer power to Ouattara, telling reporters in Nairobi, Kenya, that "there has been too much bloodshed, including hundreds of civilians killed or wounded."

U.N. deputy spokesman Farhan Haq said the U.N. High Commissioner for Human Rights has received "unconfirmed but worrying reports" that the pro-Ouattara force "has been committing human rights violations" during the advance toward Abidjan.

He added: "The human rights office also says pro-Gbagbo forces have continued to commit violations on a daily basis."

Since the disputed election, Ouattara had worked to rally international support for an armed intervention led by either the U.N. or a regional force to avoid the impression that he had taken the country by violent means. Ouattara's aides said he exhausted all diplomatic options before giving the armed group the go-ahead.

Attacking from the west, the center and the east, the fighters took towns with almost no resistance, seizing more than three-quarters of the country in four days. By the time the military vehicles crossed into Abidjan early Friday, as many as 50,000 members of Gbagbo's security forces had deserted, according to the top U.N. envoy in Ivory Coast, Choi Young-jin.

Gbagbo is still backed by the well-armed Republican Guard and several elite units.

"Do we expect him to go soon? I mean, that's impossible for us to predict from Washington, but it appears that his time is drawing nigh," said State Department spokesman Mark Toner. "We would just urge Mr. Gbagbo to read the writing on the wall."

---

Contributing to this story were Associated Press writer Michelle Faul in Johannesburg, Matthew Lee in Washington and Edith M. Lederer at the United Nations.