‘Gas attack in NY planned, called off’

The informant said the operatives had planned to use a small, easily concealed device to release hydrogen cyanide into multiple subway cars. US officials had already discovered plans for the device on the hard drive of a computer of a Bahraini jihadist arrested in February 2003, and they had been able to construct a working model from the plans.

The easy-to-make device, called the mubtakkar, meaning ‘‘invention’’ in Arabic or ‘‘initiative’’ in Farsi, represented a breakthrough in weapons technology that ‘‘was the equivalent of splitting the atom,’’ Suskind writes in his book. All previous attempts to use the deadly gas, similar to that used in Holocaust-era gas chambers, in mass attacks had failed.

The FBI declined to confirm the details of Suskind’s account. Spokesman Bill Carter in Washington said on Saturday the bureau would have no comment on the excerpted material.

A New York Police Department spokesman said authorities had known of the planned attack. ‘‘We were aware of the plot and took appropriate precaution.’’