Security was stepped up at Tri-Atate area train stations and airports on Tuesday following terrorist attacks in Brussels, Belgium.

Port Authority of New York and New Jersey spokesman Scott Ladd in a statement said Port Authority Police are increasing their presence at Newark Liberty, JFK and LaGuardia airports. "High visibility anti-terrrorist patrols are being added to the PATH system and the World Trade Center" as well, according to Ladd.

In a message on their Facebook page, New Jersey State Police said they are "in constant communication with our law enforcement partners within the State and throughout the region" following the attack utilizing the New Jersey Regional Operations and Intelligence Center. "As always, we urge the public to remain vigilant, and if you see something, say something," saidState Police.

SEPTA and PATCO had similar messages for riders to be observant of their surroundings and their fellow riders. "Look Up. Speak Up. Your eyes & ears are the 1st defense on public transit," tweeted PATCO.

Speaking on Tuesday afternoon at Monmouth Medical Center in Long Branch, Gov. Christie said there is no credible threat directed towards New Jersey and he has met with state Homeland Security. Christie said NJ Transit and Amtrak have stepped up their security at transportation hubs including Penn Station in New York and in Newark.

The NYPD is increasing visible presence of officers on the streets and in the subway system across the city's five boroughs. Former NYPD Commissioner Ray Kelly told ABC News, "Let's face it, we have lots of vulnerabilities, lots of vulnerabilities at airports especially. What we gotta do now is to as much as possible raise the comfort level of people who have to get on these airplanes."

In a statement issued Tuesday morning, the NYPD said it had deployed deployed additional counterterrorism resources across the city including its: the Counterterrorism Response Command, the Strategic Response Group, and Hercules Teams.

"These teams have been deployed to crowded areas and transit locations around the city out of an abundance of caution to provide police presence and public reassurance as we closely follow the developing situation overseas. At this time, there is no known indication that the attack has any nexus to New York City," the NYPD said.

In the same statement, the NYPD noted proposed cuts to federal terrorism funding for New York City: "Any cut in terrorism funding to New York — to what is widely recognized as the nation’s top terror target — would be irresponsible.

Explosions, at least one likely caused by a suicide bomber, rocked the Brussels airport and subway system Tuesday, prompting a lockdown of the Belgian capital and heightened security across Europe. Dozens of people were reported dead.

Belgium has raised its terror alert to its highest level, diverting arriving planes and trains and ordering people to stay where they are. Airports across Europe have tightened security. 

European security officials have been bracing for a major attack for weeks, and warned that the Islamic State group was actively preparing to strike. The arrest Friday of a key suspect in the November attacks in Paris heightened those fears, as investigators said many more people were involved than originally thought, and that some are still on the loose.

The Associated Press contributed to this report.

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