Asked what they though terrorists might do next, 37 percent said attack with chemical or biological weapons, while 18 percent expect a bombing or an attack on a public place or infrastructure.

CNN: Survey: Shock from terror attacks receding

The US believes he is one of many "foreign terrorists" given shelter in Somalia and had asked the Somali group that now controls Somalia's capital to hand him over - despite repeated denials from Union of Islamic Courts that it is not harbouring foreign Islamic fighters.

BBC: Profile: Fazul Abdullah Mohammed

"A couple of years ago, they called and asked me to come and brainstorm different ways terrorists might attack the United States, " he recalled.

WSJ: Brad Meltzer: His Plotting Pays Off | By Joanne Kaufman