The number of reports of suspicious activity in Washington increased 60 percent over an investigation of a terrorist threat just a decade after hijacked plane attacks which killed nearly 3,000 people, the capital's Police Chief Cathy Lanier said on Sunday.
"Police are checking every report," Lanier said.
On Sunday, Americans remember victims of 9/11 terrorist attacks, while law enforcement authorities in Washington and New York are on high alert against what was called by the authorities a "credible but unconfirmed" terrorist threat to the United States. The U.S. officials said the threat could involve two Americans or people traveling with American documents.
"I think that the fact that an individual, if he is involved in a terror threat or terror planning, is a U.S. citizen is concerning because we don't expect that from our citizens, but it also provides us with a little bit less visibility on people," James McJunkin, the assistant director in charge of the FBI's field office in Washington said. "We don't do surveillance on American citizens short of a criminal investigation and so we're a little bit blind sometimes about the U.S. citizens that might be involved."
In the September 11 attacks, al Qaeda's 19 men hijacked airliners and crashed them into the World Trade Center in New York, the Pentagon outside Washington and a field in Shanksville, Pennsylvania. Just weeks after that, U.S. forces invaded Afghanistan to topple that country's Taliban rulers who had harbored the al Qaeda leaders responsible for the September 11 attacks.
