Sources tell Action News the New York Police Department landed at Philadelphia Northeast Airport around 2:00 p.m. on Sunday.
Reports indicate they went to a home of a potential witness in a suburb north of Philadelphia.
NYPD Commissioner Raymond Kelly said earlier Sunday that police were planning on reviewing a video from a Pennsylvania man who may have captured the Time Square suspect.
Sources say they reviewed the video and left for New York.
Delaware & Lehigh Valleys react to bomb scare
The attempted car bombing in New York left local authorities on a heightened state of awareness.
"Our own Philadelphia Police Department continues to monitor the situation. We're in constant contact with NYPD, as well as the Federal Department of Homeland Security," Mayor Michael Nutter of Philadelphia said.
In New Jersey, Governor Chris Christie released a statement Sunday stating, "We are in contact and coordinating with New York authorities and all relevant authorities remain activated and vigilant."
The attempted terror attack has many people in our area concerned.
"I'm kind of speechless to be honest; I'm really tired of that happening, people being killed, it's like every 5 seconds, there's always something, in London or here or somewhere else," Amber Johnson of North Philadelphia said.
"It's a real shame that people want to kill each other," Alex Keller of West Chester, Pa. said.
In Philadelphia, police, state and federal authorities have been preparing for a similar attack in recent years.
Three years ago, they conducted a drill where the made-up scenario involved a car bomb exploding below the Art Museum steps.
Just last week, local responders performed an emergency response drill at the Boeing Plant in Ridley, only it dealt with a radioactive bomb.
"I think we have an excellent preparedness plan, but unfortunately, you can never really know what someone else is going to do that might mean us harm," Nutter said.
The Philadelphia Police tell Action News they have plans in place to upgrade their presence in highly populated areas and are asking the public to stay highly vigilant.
