Fighting in Ivory Coast's main city, Abidjan, has taken a new turn with reports that entrenched ruler Laurent Gbagbo's residence has been captured. Forces loyal to Alassane Ouattara, the country's internationally recognised president, said they had taken the building after a day of fierce combat. A spokesman for Mr Ouattara, Patrick Achi, told the BBC it was not yet clear whether Mr Gbagbo had been inside. Earlier, UN and French helicopters attacked targets near the residence. UN Secretary General Ban Ki-moon said the attacks were ordered to defend civilians and were not a declaration of war on Mr Gbagbo. He said Mr Gbagbo's forces had stepped up the use of mortars, rocket-propelled grenades and heavy machine-guns against civilians. Millions of civilians have been trapped by five days of fighting in the city, where Mr Gbagbo is refusing to leave office despite UN-approved results saying Mr Ouattara won November's presidential election. Forces loyal to Mr Ouattara began a dramatic military offensive last week, sweeping in from the north and west. 'Still looking' Patrick Achi, a spokesman for Mr Ouattara, said the recognised president's forces were in control of the residence and searching for Mr Gbagbo. "The residence is on many levels," he told the BBC. "People have seen that Gbagbo was in the residence but they are still looking for him." Asked what would happen if Mr Gbagbo was captured, he said he would be arrested and "brought to justice". There was no word from Mr Gbagbo's camp in Ivory Coast but one of his advisers in London, Abdon George Bayeto, expressed doubt about news the residence had fallen. "This is all propaganda and it is all a war of psychology," he said. Earlier, UN and French helicopters attacked Mr Gbagbo's arsenal, firing missiles at his heavy weapons and military camps. A senior peacekeeping official, Alain Le Roy, said the decision had been based on a strongly worded UN Security Council resolution authorising such action to protect civilians. The use and calibre of heavy weapons by Gbagbo forces had, he said, escalated sharply in recent days. The UN mission had been under almost continuous attack and had been forced to act, he said. However, the air strikes coincided with what looked like a final assault on Mr Gbagbo's last strongholds by forces loyal to his rival Mr Ouattara, the BBC's Barbara Plett reports from the UN in New York. Observers said the timing might not have been a coincidence as there was a sense that the months-long stand-off between the two presidential claimants was nearing its end. Source: BBC