Authorities investigating a suspected al Qaeda plot to set off bombs in the U.S. are warning local law enforcement agencies that hotels, stadiums and entertainment complexes remain attractive targets for attacks.
Two bulletins from the FBI and the Homeland Security Department were sent to local law enforcement agencies Monday, the same day three men were arraigned on charges of lying to the FBI in connection with the bureau’s investigation of the purported plot. The bulletins did not mention the recent arrests.
The scope of the suspected scheme remains unclear. Authorities have said the investigation centers on “several people” in the United States and Pakistan who wanted to detonate improvised explosive devices in the U.S.
“This has got a bunch of people spooked,” said a Homeland Security official who asked not to be identified because of the sensitivity of the investigation. “They don’t believe they got them all; they are trying to track down the rest of the guys who are operating in the cell.”
The official said law enforcement agencies have been told to be aware of their surroundings to make sure they are not under countersurveillance.
A defense counterintelligence official familiar with the situation said the quick arrests of the three men leave unanswered many “extremely alarming” questions about the scope of the plot. Three people “is not enough to do any serious plot,” he said.
“It’s more what we don’t know,” he said. “We still don’t know — and this is the scary part — how many people are still at large.”
The official, who spoke to The Washington Times on the condition of anonymity, said reports of investigators seizing a large number of backpacks from an apartment in New York where Najibullah Zazi had stayed would suggest a far broader conspiracy.
A second Homeland Security official said security has been increased at some international airports with uniformed officers, as well as in the Metro Transit System in New York.
Homeland Security has not altered the threat levels on its color-coded advisory system, which remains yellow or “elevated” for the general threat of terrorism, and orange or “high” for airline flights.
The bulletins issued Monday come on the heels of a warning issued late last week advising local law enforcement to remain vigilant about the threat of homemade explosives to mass-transit systems. It noted that overseas incidents frequently used peroxide-based improvised explosive devices hidden in backpacks.
Authorities last week seized backpacks and cellular phones from apartments in the New York borough of Queens, where Mr. Zazi, a central figure in the investigation, had visited. The fatal train bombings in London and Madrid were carried out with bombs hidden in backpacks and detonated by cellular phones.
Authorities said Monday that the bulletins were simply meant to assist local law enforcement and were not meant to be released to the media.
“While DHS and FBI have no information regarding the timing, location or target of any planned attack, we believe it is prudent to raise the security awareness of our local law enforcement partners regarding the targets and tactics of previous terrorist activity,” according to a public statement released Tuesday by the Department of Homeland Security and the FBI. “As always, the American people should remain vigilant and report any suspicious activities to their local authorities.”
The arrests Sunday of the three Muslim men played out in an unusually public fashion after several apartments in Queens were raided last week and Mr. Zazi, a 24-year-old legal permanent resident from Afghanistan, began giving interviews to media outlets and met voluntarily several times with FBI agents.
Authorities charged Mr. Zazi with lying to the FBI because, they said, he claimed he didn’t know about the handwritten notes on making bombs found on his computer. Authorities say handwriting analysis indicates Mr. Zazi wrote the notes.
The FBI said Mr. Zazi also admitted receiving weapons and explosives training at an al Qaeda training facility in Pakistan, though he does not face any charges related to that trip. Mr. Zazi has told media outlets that he went to Pakistan to visit his wife.
Authorities revealed in court documents filed Monday that investigators had been monitoring Mr. Zazi pursuant to the Foreign Intelligence Surveillance Act, which is used when investigators think a suspect is involved in a conspiracy involving people overseas.
Authorities appeared to tip their hand about the investigation when detectives from the New York Police Department visited an imam who has cooperated with other investigations and showed him pictures of Mr. Zazi and other apparent suspects. The imam, 37-year-old Ahmad Wais Afzali, told Mr. Zazi and his father, 53-year-old Mohammed Wali Zazi, about the visit from law enforcement.
Mr. Afzali and Mohammed Zazi were charged with lying to investigators about conversations they had with each other and the younger Mr. Zazi after learning about the investigation. Authorities have not released any information linking Mr. Afzali and the elder Mr. Zazi to the purported plot.
Victor Morton contributed to this report.