ABIDJAN, Ivory Coast (AP) — French tanks advanced toward the bunker where Ivory Coast's strongman leader hung on to power Monday, marking the first time that forces from the former colonial ruler have become involved in the ground operation to oust him.

The French tanks rolled into Abidjan's city center one day after a second aerial bombardment struck his positions around the city. Forces loyal to internationally recognized President Alassane Ouattara joined the battle, attacking positions around the state television station and Gbagbo's home, local residents said, speaking on condition of anonymity for fear of reprisal.

Only several hundred yards (meters) from Gbagbo's mansion, locals said at least 10 armored vehicles flying the French flag drove through the neighborhood Monday morning, sending pro-Gbagbo gunmen fleeing. Two tanks took up a position at a key intersection, while the others advanced toward Gbagbo's home.

Not far away, pro-Ouattara fighters pushed toward the state television station in what appeared to be a coordinated action. However, a French military representative who asked not to be named because he is not permitted to comment on ongoing operations, denied that there was any coordination with Ouattara's forces.

There was no immediate comment from the French Defense Ministry on Monday's operations.

Not far away in the downtown Plateau business district, witnesses said they saw French vehicles and French soldiers clashing with pro-Gbagbo forces around the presidential palace.

An Associated Press reporter saw a column of 25 military vehicles including tanks and armored personal carriers leaving a French army base earlier Monday morning. Helicopter gunships flew repeated missions during the day and explosions echoed miles (kilometers) away.

The head of the United Nations and French President Nicolas Sarkozy authorized Sunday's helicopter strikes that continued late into the night, accusing Gbagbo of continuing to use heavy weapons against civilians in his bid to hang on to office more than four months after losing the presidential election.

A U.N. Security Council resolution passed last month authorized the use of force and Sunday's attack was the second round of aerial bombardments to that end.

Gbagbo has lost control of virtually the entire West African country over the last two weeks as forces loyal to internationally recognized winner Ouattara have swept down from the north and west into the commercial capital of Abidjan.

U.N. and French forces then joined the effort, and a first round of U.N. and French airstrikes destroyed much of his arsenal of tanks, mortars and other heavy weapons last week.

Forces loyal to Gbagbo had been encircled at the presidential residence but broke out on Saturday, ambushing a patrol of pro-Ouattara soldiers and advancing downtown. Pro-Gbagbo forces also attacked U.N. headquarters and the hotel where Ouattara's administration is based.

(Photo: AP Photo/Rebecca Blackwell)