By SARAH KARUSH; Associated Press The random screening will not require passengers to arrive earlier, Amtrak officials say.

NEW YORK - With the London bombings fresh in their minds, police along Amtrak's New York-Washington corridor joined forces Monday to begin patrolling the train platforms and watching for suspicious activity along the tracks.

NYPD begins policing Amtrak trains as security precaution NEW YORK, July 18 (Xinhua) -- The New York Police Department (NYPD) has tightened the security of mass transit systems by policing Amtrak trains Monday at New York's Penn Station, in response to the terror attacks in London earlier this month.