UN, France target Ivory Coast’s Gbagbo (UPDATES) (VIDEO)

Besieged Ivory Coast President Laurent Gbagbo was reportedly trapped in a bunker underneath his residence early Tuesday negotiating a possible surrender as U.N. and French helicopters attacked targets at his residence, offices and military bases.

The Associated Press reported that forces backing Ivory Coast's democratically elected leader, Alassane Ouattara, had seized the presidential home.

The bombardment against Gbagbo, who has refused to step down after a presidential election in November, comes as Ivory Coast's political crisis and post-election turmoil have reached what appears to be a turning point. 

Forces loyal to Ouattara, whom the international community recognizes as the winner of the election, have made gains across the country in the past week. About 5,000 of Ouattara's forces entered Abidjan, the main city and commercial capital, on Monday in preparation for a final advance against Gbagbo.

Explosions and gunfire could be heard around Abidjan as attack helicopters fired at Gbagbo's military bases and residence, Reuters reported. The French military was targeting Gbagbo's weapons stockpiles and armored vehicles.

France said it was carrying out the attacks at the request of the United Nations.

The strikes represent a significant escalation of international involvement and a rare instance in which the United Nations has used force against a conventional army, the Washington Post reported.

Alain Lobognon, a spokesman for the prime minister, Guillaume Soro, told the New York Times that the attacks forced Gbagbo into his residence's bunker, from where he was negotiating a possible surrender through a French ambassador.

He said Gbagbo's rule would soon be over.

"Our forces have made significant advances,” he told the Times. “In a few hours it will be all over. We came into the city of Abidjan today, and I think it will soon be finished.”

A spokesman for Ouattara's forces, Patrick Achi, told Reuters that Ouattara's people had seized Gbagbo's residence, but the information could not be independently verified.

Achi told the BBC that if Gbagbo is captured, he will be arrested and "brought to justice."

The U.N. withdrew non-essential staff earlier Monday amid reports of a massacre, and after 11 peacekeepers were shot during fighting in recent days. The Special Representative in Ivory Coast of the U.N. Secretary General has accused pro-Gbagbo forces of "mindless" attacks on the U.N. base in Abidjan, according to the BBC.

"We are planning action, we can no longer condone their [Gbagbo's forces] reckless and mindless attack on civilians and the United Nations blue helmets with heavy weapons," the BBC quoted Choi Young-jin as saying. "We are now in a way under siege, so we cannot go out freely, [they're] targeting us with snipers, it's a deliberate shot at United Nations."

U.N. Secretary General Ban Ki-moon insisted that the United Nations is not "party to the conflict" and was only acting in self-defense and to protect civilians. He said the strikes come after Gbagbo's forces used mortars, grenades and machine guns against the civilian population and attacked the U.N. patrols and headquarters in Abidjan, the New York Times reported.

About 1 million people have fled Ivory Coast due to the ongoing violence, and about 4 million remain in Abidjan, many trapped in their homes as they run out of food and supplies. Thousands have been killed in the fighting.

— Hanna Ingber Win