The Metropolitan Transportation Authority and Port Authority are ramping up security at subways, airports, bridges and tunnels.
There was heavy artillery underground Monday as multiple police agencies and the National Guard look for any signs of trouble at Penn Station and other major transit hubs across the city.
The Metropolitan Transit Authority, NYPD and Amtrak officers covered the maze of walkways at Penn Station, along with landmarks and key financial centers .
Police Commisioner Ray Kelly said there were no specific threats against the city, subway system or commuter railroads Monday morning.
"We certainly are not taking any chances,” Kelly said. “Our assumption is that bin Laden's disciples would like nothing better than to avenge his death by an attack on New York."
With that in mind extra transit officers were put on overtime to help keep a watchful eye out for any terrorist activity during rush hours
The MTA also announced stepped up safety measures saying, "... in coordination with local, state and federal law enforcement partners, we have increased security at key locations across the MTA's transportation system and remain on high alert."
But some commuters say they don't feel all that safe against potential terrorists attacks especially underground and above ground, there are more shows of force by the NYPD at certain locations like at Rockefeller Center.
Anti-terrorism officers with machine guns at the ready. There are also those security measures not seen.But police say if you see something, say something.
Airports in the city and across the country also remain on high alert.
Despite a warning from the U.S. State Department for all international travelers, everything appeared calm at John F. Kennedy International Airport and ticketholders told NY1 they were not afraid to fly today.