Hillary Clinton says al Qaeda is behind the unconfirmed threat to the United States.




The US Secretary of State was speaking at a college of criminal justice in New York. Dozens linked to it died on September 11, 2001. A rusty, twisted remainder of the World Trade Center will serve as a permanent memorial there.




'Ten years later, we have made important strides,' Clinton said in her speech. 'Our government is better organised. Our defences are safer than on 9/11, but we still face real threats, as we see today, and there is more work to be done.'.