US on full alert on 9/11 anniversary

The FBI is warning police and the US utility, banking and transportation industries of a steady stream of threats mentioning New York, Washington and the anniversary of the 11 September attacks.

US military bases and diplomatic missions world wide also are being placed on high security alert for the week, officials have said.

The flurry of incoming threats picked up by intelligence sources is challenging the FBI to determine which might be credible. But while officials say they have no specific details outlining an impending attack, the government is taking no chances.

The White House press secretary has said that the threat of new attacks remains a worry to US officials.

"Anniversaries can be - not necessarily always - can be occasions for heightened terrorist activity," he said. "Just given the fact that it's a one-year anniversary, we're going to be on our toes."

Last week, the FBI posted a bulletin on a Web site and sent a message over a private law enforcement bulletin system advising a state of alert on 11 September.

The police bulletin was sent last Wednesday, according to a law enforcement official who spoke on condition of anonymity.

The Web site bulletin was posted by the FBI's National Infrastructure Protection Center, which assesses threats and passes warnings to local infrastructure companies and agencies. Banks, trucking companies, power companies, utility companies and transportation companies are in the network that the FBI communicates with through Internet bulletins.

Other events mentioned on the Web site as warranting heightened awareness include the 10-20 September UN General Assembly session in New York and the 25-29 September World Bank and International Monetary Fund meetings in Washington.

"A large volume of threats of undetermined reliability continues to be received and investigated by the FBI," the bulletin said. "Several of these threats make reference to the events of Sept. 11, 2001, and to New York City and Washington, D.C."

The warnings are based on information from all US intelligence sources, from telephone calls to interviews with detainees at the US Naval Base in Guantanamo Bay, Cuba, according to a senior law enforcement official.

Information from detainees, most of whom have been out of circulation for months, has proven false before. US officials have said they act on it only when corroborated through multiple sources, but officials said advising caution still is necessary, officials said.

In the run-up to the 11 September anniversary, US intelligence agencies have detected a mild increase in terrorist "chatter" - that is, monitored communications and other information used as a barometer of the likelihood of potential attacks.