Metro

Cops’ keen bomb prep

Police brass have ordered extra bomb-detection training for cops as officials yesterday revealed that an al Qaeda-linked terror cell may have been targeting the city’s subways.

The increased training came as the feds issued alerts to regional transit systems, stadiums and hotels to look for suspicious activity, although officials say there is no imminent threat.

Patrols in Grand Central Terminal and other potential targets were beefed up, while beat cops this week began watching a new in-house video on how to spot homemade-bomb labs, NYPD officials said.

Law-enforcement officials said they believe that alleged terrorist Najibullah Zazi, 24, was going to hide homemade hydrogen-peroxide bombs in backpacks and attack the subway. Suicide bombers behind the deadly London bombings in 2005 used homemade ingredients and backpacks.