VOWING to strike with a hammer of vengeance, the United States hunted for those behind the deadly attacks on the World Trade Center and the Pentagon – with exiled Saudi-born militant Osama bin Laden as the prime suspect. In New York, officials sought 6 000 body bags as rescue workers sifted through the rubble of the World Trade Center, twin 110-story towers reduced to smoldering wreckage after Tuesday’s suicide strike by hijacked passenger jets. Meanwhile, US agents searched homes and businesses in Florida in connection with the terror attacks, focusing on an aviation school where two suspects may have received flight training, police and media said. US stock markets will remain closed for a third day on Thursday. Full or partial equities trading will resume as early as Friday and no later than Monday, New York Stock Exchange Chairman Richard Grasso said. Trading in US Treasuries is set to reopen on Thursday. In Washington, the International Monetary Fund said it expected only a limited impact on the global economy from the attacks and that it stood ready to help countries that may need help. – Reuters