Counterterrorism officials have issued security bulletins to police around the nation about terrorists' desire to attack stadiums, entertainment complexes and hotels - the latest in a flurry of such internal warnings as investigators chase a possible bomb plot in Denver and New York.In the two bulletins sent to police departments Monday, officials said they know of no specific plots against such sites but urged law enforcement and private companies to be vigilant. The bulletins came after a similar warning about the vulnerabilities of mass transit systems.
The bulletin on stadiums notes that an al Qaeda training manual lists "blasting and destroying the places of amusement, immorality, and sin ... and attacking vital economic centers" as desired targets of the global terror network.
Law enforcement bulletins - particularly about hotels as possible targets - are common, aren't intended for the public and often don't make news. But a half-dozen alerts issued in the past week have received increased attention amid the investigations in New York and Denver. The first of these, about hydrogen peroxide-based explosives, specifically referred to the investigation in New York.
Separately, law enforcement officials said a Colorado man may have been planning with others to detonate backpack bombs on New York City trains in a terrorism plot similar to past attacks on London's and Madrid's mass-transit systems.
The investigation and the earlier warning about mass-transit systems have prompted officials around the nation to step up patrols.
New York City's transit agency said it increased police presence around the city in light of the ongoing probe and the law enforcement notices.
In the Bay Area, BART and San Francisco's Muni continue to conduct measures that include random sweeps of trains and the use bomb-sniffing dogs, officials said.
Two law enforcement officials speaking on condition of anonymity because they were not authorized to discuss details of the investigation said more than a half-dozen individuals were being scrutinized in the alleged plot.
Investigators say Najibullah Zazi, a 24-year-old Afghanistan-born immigrant who is a shuttle van driver at the Denver airport, played a direct role in the plot, which unraveled after a 1,600-mile trip from Denver to New York City around the anniversary of the Sept. 11 attacks.