(The New York Times posted the following article by Eric Lichtblau on its website on April 2.)
WASHINGTON — Federal officials are warning local police nationwide that terrorists might try to bomb buses or trains in major American cities this summer, but they cautioned that they had no specific or credible information about any plots.
In a bulletin sent to law enforcement officials around the country on Thursday night, the F.B.I. and the Department of Homeland Security said they had received uncorroborated intelligence information “on an alleged plot against major U.S. cities in the summer of 2004” that could single out commercial transportation systems like trains and buses by using improvised explosives.
Officials described the bulletin as precautionary. The intelligence information that generated the report “is not corroborated and it’s vague, but we’re taking into account the events we’ve seen in the last few months or so and putting it out there for local law enforcement to look at,” a senior F.B.I. official said.
The F.B.I. has warned many times since the Sept. 11 attacks that Al Qaeda and other terrorist groups are likely to single out commercial transportation like planes, trains and buses, but that concern has been heightened in recent weeks by last month’s rail bombings in Madrid.
Federal officials are also concerned about the possibility of terrorist strikes at the political conventions in Manhattan and Boston and are working with state and local police to coordinate security.
Thursday’s bulletin did not mention specific cities as potential targets, but it urged local police to take extra steps to ensure security on city transportation.
Senator Hillary Rodham Clinton, Democrat of New York, cited the alert at a news conference she held in Penn Station in New York to call for passage of legislation that would provide $570 million to upgrade New York’s six aging rail tunnels.
“I think it’s imperative that we do everything possible to keep travelers on our railways safe,” she said. The money in the legislation would be used to upgrade communications systems, improve ventilation and build evacuation routes in the tunnels, which were built in 1910.