Police are increasing their presence in U.S. cities including Washington, D.C., and New York in the wake of deadly explosions at an airport and subway station in Brussels.
The attacks killed at least 26 people and put the Belgian capital on its highest terror alert level.
In the U.S., Homeland and FBI officials are monitoring the unfolding events in Brussels closely and Attorney General Lorretta Lynch has been notified of the attacks, senior law enforcement officials told ABC News.
ABC News senior justice correspondent Pierre Thomas said U.S. officials have been briefed and there is “no specific threat to the United States that we know of.”
What U.S. officials are most concerned about today is copy cats — people who could be inspired by what they’re seeing overseas — Thomas said on “GMA” this morning.
“The FBI has been monitoring roughly 100 people, 24-hour surveillance, who they think could be inspired by what they’ve been seeing in Europe,” he said.
The Port Authority police department is stepping up security at its three major airports — JFK, LaGuardia and Newark Liberty International — with heavy weapons. It’s also employing high visibility anti-terrorist patrols at the PATH train system and the World Trade Center.
“The New York City Police Department is closely monitoring the situation in Belgium and is in close contact with our international partners and with the FBI,” NYPD Deputy Commissioner Stephen P. Davis said in a statement.
“Until we learn more, the department has deployed additional counterterrorism resources across the city,” Davis said. “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.”
ABC News contributor and former New York City Police Commissioner Ray Kelly told ABC News this morning that New York City is always on high alert.
“You’ve had the two major attacks here. You’ve had at least 20 terrorist attempts here in New York City,” he said. “[The city] has the unique capacity to put out a lot of uniformed officers on the street, critical response command, an overlay of police officers.”
He added: “New York has the biggest subway system, arguably in the world. Six million people travel that system everyday, so you want to increase your uniform presence. Obviously lots of things that are going on that you won’t’ be able to see.”
In the Washington, D.C., area, the Metro Transit Police increased its presence this morning.