No 'specific or credible threats' linked to 9/11 anniversary: FBI chief

WASHINGTON: The Federal Bureau of Investigation said on Thursday that it has picked up no "specific or credible threats" linked to the anniversary of the September 11, 2001 attacks on the United States.

FBI director James Comey said it was closely watching for threats from al Qaeda or Islamic State, but told a conference on intelligence "there are not any specific or credible threats tied to tomorrow."

Friday is the 14th anniversary of the attacks that brought down the World Trade Center in New York and destroyed part of the Pentagon, killing nearly 3,000 people.

The attack by al Qaeda militants flying hijacked airliners was the deadliest ever on US soil, and propelled the United States into an era of wars in Afghanistan and Iraq.

Admiral Michael Rogers, head of the National Security Agency, said September 11 was "clearly a date that resonates for a lot of people."

"You hear groups talking about the significance of that date," he said at the same conference. "But I wouldn't say that it is as high as I have seen... in the last 14 years."