By Ange Aboa and Loucoumane Coulibaly
ABIDJAN (Reuters) - French and U.N. helicopters attacked heavy weapons of troops loyal to Ivory Coast's incumbent president Laurent Gbagbo Sunday and Gbagbo's spokesman said his residence had been partly destroyed.
"U.N. and French helicopters continue to fire at President Gbagbo's residence which has been partially destroyed," Ahoua Don Mello said by phone.
"There is thick smoke coming from it, but we have no other details on the damage," he said. He declined to say whether Gbagbo was at the residence at the time.
UN Secretary-General Ban Ki-moon said he had ordered the UN peacekeepers to use "all necessary means" to stop Gbagbo's forces using their heavy weapons.
"We are pursuing our operation to neutralise Gbagbo's heavy weapons," U.N. mission spokesman Hamadoun Toure told Reuters.
"We had to stop the operation for a couple of days to evaluate and have realised that there are still some heavy weapons that they had used against civilians and the U.N."
A Reuters correspondent at the French military base near the airport, about 15 km from Gbagbo's residence, said he could hear loud explosions coming from the direction of the fighting. He said four helicopters, two U.N. and two French, were carrying out operations.
A resident of Cocody neighbourhood where Gbagbo's residence is situated said he could see thick black smoke coming from the building.
Forces loyal to Gbagbo had stepped up a counter-attack on presidential claimant Alassane Ouattara by firing on his hotel headquarters in Abidjan Saturday. The hotel is guarded by U.N. forces.
Residents near the presidential palace and Gbagbo's residence where he is said to be holed up with his family, close advisers and about 1,000 militiamen, said they heard heavy cannon fire and shooting late Sunday afternoon.
In Paris, lawyers for Ouattara in a letter to the French government and the international community Sunday, asked United Nations and French forces to eliminate Gbagbo's heavy weapons and militia and bring him to justice.
Rebel forces trying to install Ouattara, who won an election last November according to results certified by the United Nations, swept from the north to coastal Abidjan almost unopposed more than a week ago.
But despite a fierce rebel onslaught, Gbagbo's soldiers have held onto swathes of the city and launched a counter-attack on his hotel.
Even if Gbagbo leaves, Ouattara's ability to unify the West African country, the world's No.1 cocoa producer, may be undermined by reports of atrocities against civilians since his forces charged into Abidjan. Ouattara's camp has denied involvement.
A U.N. spokesman in Abidjan said Saturday's attack on the Golf Hotel, which Ouattara has made his base since the election, involved heavy weapons that appeared to have been fired from Gbagbo's heavily defended residence.
"This was not a fight, but a direct attack by Gbagbo's forces, who fired RPGs (rocket-propelled grenades) and mortar rounds, from positions near Gbagbo's residence, at the Golf Hotel," said U.N. spokesman Toure.
He said one U.N. peacekeeper had been hurt, and U.N. forces had responded by firing on those positions.
(Additional reporting by Emmanuel Braun in Abidjan, Tim Castle in London, Patrick Worsnip and Louis Charbonneau at the United Nations, Bertrand Boucey and Elizabeth Pineau in Paris, Stephanie Nebehay in Geneva; Writing by Bate Felix and Richard Valdmanis; Editing by Tim Pearce)