The US Department of Transportation has issued a warning about possible attacks on rail and transit systems across the country, law enforcement officials said last night.
The department's warning was based on unconfirmed and uncorroborated information, one law enforcement official said.
"It involves rail and transit systems ... and is about possible attacks," he said.
The Department of Transportation consulted the FBI before issuing the warning, but the FBI did not put out a matching alert or advisory to law enforcement officials across the country, the official said.
He did not have details on how many cities' transit systems were being put on alert.
Transportation Department spokesman Chet Lunner said that although the general threat was made against subway systems and no particular cities were targeted, the department decided to expand its advisory to include rail systems across the country as well.