The FBI and New York City Police don't yet have specific information on timing or targets, but an urgent investigation is said to be picking up speed on what could be the first terrorist operation on US soil since 9/11 that's linked to al Qaeda. Three arrests have been made so far, two near Denver, Colorado, the other in Queens, New York. Three native Afghans, living legally in the US, are charged with deliberately making false statements to federal agents. Josh Meyer covers terrorism for the Los Angeles Times.