NEW YORK (AP) --Some of the nation's busiest transit systems are boosting security after today's attacks on Moscow's subway system.
Special New York Police units in black helmets and body armor have been assigned to transit facilities. Mayor Michael Bloomberg says security is changed every day, but he wouldn't give details.
Atlanta's police department also has more officers patroling the city's public transit system.
A Chicago Transit Authority spokesman says personnel are watching closely for anything suspicious. And in Washington, Metro police are conducting random checks of stations and rail yards.
Transit officials in Boston and Philadelphia say they believe normal security practices are strong enough to protect the riding public.
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