And now for the rest of the story from CNN:
Sources: N.Y. subway threat tip a hoax
From Kelli Arena
CNN Washington Bureau
WASHINGTON (CNN) -- Information that led to heightened security for the New York City transit system was a hoax, government sources said Tuesday.
The sources said an informant in Iraq who provided the tip had told investigators about a terrorist plot involving New York's subway system. After various investigations, the sources said, officials have determined the informant gave false information.
On Monday, law enforcement officials said they could not corroborate any of the informant's claims. That prompted the New York Police Department to scale back the increased security measures put in place on the city's subways last week.
Government sources said the three men arrested in Iraq with suspected links to the possible plot had been interviewed and underwent lie detector tests showing they knew nothing about such a plan.
New York Mayor Michael Bloomberg warned Thursday that the city had received information from the FBI about a "specific threat," prompting the heightened subway security.
The threat mentioned Friday and Sunday as possible days that an attack might occur, according to one official with knowledge of the investigation.
In addition, information alleging that someone involved in a possible New York plot had entered the United States has not been corroborated. "We still do not know if such a person even exists," an official said.
Law enforcement sources said the informant had provided some accurate information in the past and therefore his latest tip was given serious attention.
Friday came three months to the day after four bombers carried out attacks on three London, England, subways and a double-decker bus, killing 52 people and wounding 700. (Full story)
After Bloomberg's warning, some intelligence officials played down the New York information, saying it was not credible.
On Tuesday, Bloomberg said city officials couldn't wait until a threat materialized to act.
"We have to protect this city. We can't just sit around with your fingers crossed," Bloomberg said. "We have to make decisions and show leadership. And that is exactly what we have done. And if given the same situation we would do exactly the same thing."