24-year-old Najeeboolah Zazi was in federal court Monday in Denver where he was ordered held until a detention hearing on Thursday. Investigators fear that Zazi may have been involved in a plot to use hydrogen peroxide-based explosives to attack mass transit trains in New York. They say Zazi received al-Qaeda training in Pakistan last year.
Investigators are still trying to track down the others believed to be involved in the terror plot. Amtrak and the Transportation Security Administration have racked up security along Amtrak's northeast corridor. Action News has learned it is an intense operation that spans several states.
Law enforcement officials say Amtrak has no information on a specific threat but as a precautionary measure and until further notice Amtrak, TSA and other federal and state agencies have increased security on the rail line. This as the FBI and CIA continue to search for other members of the alleged terror plot.
Authorities tell Action News the beefed up security measures include more K-9 units and random baggage inspections in Amtrak facilities in Washington D.C. and 13 states including Pennsylvania, New Jersey and Delaware.
Authorities say Zazi, the apparent ring leader, has admitted traveling to an al-Qaeda training camp in Pakistan where he received instructions on weapons and explosives. They believe he came back to carry out a 9-11 style attack. In addition to the arrests of his father, Mohammed Zazi and New York Imon Ahmad Afzali, law enforcements agents tell ABC News they're watching a number of other people around the clock who they suspect may also be part of the terror plot.
The heightened security measures have also made some rail users more alert about what's going on around them. That's exactly what authorities want people to do. The commanding officer of the Philadelphia Police Department's Homeland Security Unit is asking people to remain diligent in preventing potential terrorism or criminal activity and immediately report all suspicious activity to 911.
You can get the latest crime statistics from the Philadelphia Police by CLICKING HERE for the force's crime data mapping site.