leader osama bin laden has been urging affiliates of his terrorist network the take action, but one source cautions of linking bin laden to recent reports that he ordered mumbai-style attacks on european cities. the hub came under a series of uncoordinated attacks two years ago that left 160 people dead. could such a multipronged assault happen here in the united states? would the u.s. be ready to take them on? here is cnn's homeland security correspondent jeanne meserve. >> wolf, this is a colt m-4 semi-and fully automatic weapon and now every new york city police recruit is shown how to use one. why? mumbai. >> reporter: mumbai was a low-tech, high-impact attack, and terrorists armed with only semi-automatic weapons an grenades and bombs hit many