Terrorists may try to use fuel tankers as weapons to attack Jewish neighborhoods, synagogues and fuel depots, the FBI advised law enforcement agencies on Friday.
Officials stressed that the advisory was based on unsubstantiated and uncorroborated information and was not a warning to the general public, but rather an advisory issued to local police departments.
"People should still go to temple," an official told Fox News. "This is similar to the information that was circulated about the possible targeting of shopping malls or apartment buildings."
"I don't think Jewish communities would be surprised to hear that they could be targeted," the official added.
A Bush administration official, speaking on condition of anonymity, said the warning concerns potential attacks against U.S. interests in America or abroad.
The notice to law enforcement agencies said:
"Law enforcement agencies are encouraged to make contact with appropriate Jewish community representatives and officials and trucking and fuel delivery facilities that operate fuel tanker trucks or commercial fueling stations and emphasize the need to report suspicious activities or persons."
Bush administration officials stressed that the information is as unspecified and as uncorroborated as intelligence that led to similar alerts concerning shopping malls and banks in recent weeks.
Officials said the nation's overall alert status is still unchanged from code yellow, which is the third-highest stage of alert.
The advisory was sent across the National Law Enforcement Telecommunications System, an electronic system that allows the FBI to send alerts or messages to police in all 50 states simultaneously.
It warned that terrorists might be interested in using fuel trucks as weapons and said any property inside the U.S. and abroad could be a target — but it specifically mentioned Jewish neighborhoods, synagogues and fuel depots.
The advisory was based not on a specific threat, but on interviews with captured Al Qaeda and Taliban fighters who indicated such a plot had been discussed, officials said. The interviews with detainees did not reveal a target city or time.
"Even if unconfirmed, we analyze incoming information as quickly as possible and if we think there is any chance it could be helpful, we make the decision to send it," one official said.
The Homeland Security office approved the message before it was sent, according to the official. The FBI's 56 field offices also were made aware of the advisory.
The FBI has initiated several nationwide efforts to disrupt possible terrorist plots in recent weeks.
Agents have been contacting hundreds of scuba diving shops out of concern the next wave of terrorist attacks could be carried out by divers.
The FBI said it is looking into whether Al Qaeda operatives have been taking scuba training in order to blow up ships at anchor, power plants, bridges, depots or other waterfront targets.
Also, a maintenance worker who said he wanted to buy a replica ambulance for tool storage triggered an FBI warning in two states that terrorists might try to use emergency vehicles in an attack. After interviewing the man, the FBI found he had no such plan.
Law enforcement officials were contacted about two weeks ago, after two men walked into Movie Time Cars Inc., a company that rents replicas of ambulances and police cars to TV and film producers.
Officials have expressed concern about possible fuel-truck hijackings ever since the Sept. 11 terror attacks.
The Associated Press contributed to this report.