Dr. Sebastian Gorka said that today's terror attack at a subway platform near Times Square should serve as a reminder to all Americans to stay alert at all times.

Gorka, a counterterrorism expert and former Trump White House official, emphasized that people need to avoid walking in public while looking down at their cell phone. 

"If you can't flee, you must hide. If you can't hide, you must fight, whether it's with a fire extinguisher or your bare hands. Everybody has to resist these people and understand that we will not be sheep. It is the sheep that are the best targets for terrorists," he said on "Fox & Friends."

The suspected bomber is a 27-year-old ISIS-inspired Bangladeshi national who lived in Brooklyn, The New York Post reported. Akayed Ullah was injured and taken into custody, according to the NYPD.

Three others were hurt, but none of the injuries are considered life-threatening.

The device was detonated on a subway platform near Port Authority Bus Terminal, which was quickly evacuated. The device was strapped to the bomber.

Gorka said people should not live in fear, but must remain alert and have a plan in case they find themselves in the middle of a terror incident or an active shooting.

Former U.S. Secret Service officer Dan Bongino agreed, also advising people to be aware of their surroundings, especially in crowded places.

"Keep your head on a swivel a little bit. Always have a plan," he said. 

This is the second terror attack to strike New York City in recent weeks. On Halloween, an Uzbek man drove a van through a crowd of cyclists and pedestrians in lower Manhattan, killing eight people and injuring 11.

Watch more above and read more on the bombing, here.

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