NEW YORK (CBSNewYork) — Hundreds of emergency responders converged on a lower Manhattan subway station Sunday morning — but it was only part of a test.

The NYPD, FDNY and Homeland Security held a three-hour active-shooter drill at the Bowery subway station.

READ MORE: Sharee Jones Charged With Arson, Hate Crime After Fire At Brooklyn Yeshiva

Police blocked off the area near Kenmare and Broome streets while they went down into the closed station, CBS2’s Ilana Gold reported.

The scenario: Two officers initially respond to a report of a man with a gun on the platform and call for backup. After there is a mass callout, emergency responders face many dangerous mock surprises and the possibility of several shooters.

Wearing protective gear, they fired high-powered weapons loaded with blanks, 1010 WINS’ Roger Stern reported.

Outside the station, cops with black helmets and heavy-duty vests could be seen with K-9 units, and there were police and fire vehicles lining the streets, WCBS 880’s Peter Haskell reported.

The drill was planned before the Paris attacks. According to NYPD Chief James Waters, elements similar to the Paris attacks were added as part of the planned exercise at the last-minute as well, CBS2’s Matt Kozar reported.

Mayor Bill de Blasio, NYPD Commissioner Bill Bratton, FDNY Commissioner Daniel Nigro and Homeland Security Director Jeh Johnson were on hand to watch the drill.

Bratton said he thought it went well.

“Today’s exercise was designed to test the coordination between our resources as well as the Fire Department,” Bratton said.

“In New York City, we are, at this time, very well prepared and continually improving that preparedness.”

Officials will review video of the drill to see what, if any, changes should be made.

“You see more coordination, more team work than ever before,” de Blasio said.

The Department of Homeland Security provided funding for the drill because of concern that a lone wolf could attack in the U.S.

“We know of no specific credible threat of a Paris-like attack directed at the U.S. homeland,” Johnson said. “We are and we continue to be and we have been concerned about copycat-like attacks.”

Johnson said Americans should travel and attend public events this holiday so the terrorists don’t prevail.

READ MORE: NYPD: Delivery Worker Stabbed To Death, E-Bike Stolen Near Sara D. Roosevelt Park

“Terrorism cannot prevail if the people refuse to be terrorized,” Johnson said.

There has been heightened security in the subways since the terror attacks in France to ensure commuters are safe. Even Bratton took a ride, sending a message to the public about the city’s security.

Heavily armed police with bomb-sniffing dogs have been on guard in Times Square and in other congested areas of the city, along with landmarks.

In Hell’s Kitchen, CBS2 talked to diners about their sense of security.

“I actually don’t have second thoughts,” said Sara Al Mouswai, of Boston. “I’m continuing living my life. Terrorism happens all around the world, and you just have to be cautious and on the lookout.”

The city will be especially cautious during this week’s Macy’s Thanksgiving Day Parade, where millions will line the streets of Manhattan. Visitors can expect tight security.

Bratton said thousands of officers will patrol the parade route, including an additional 1,300 counterterrorism officers. 

“For a change we’re going to have great weather, balloons will be up,” Bratton said. “We expect about three million people to be in New York City for the event.”

In Brussels, police and soldiers patrolled the city after warnings of a possible terror attack similar to what happened in Paris.

Subways remained closed and many activities and events were cancelled as people were urged to stay home.

Officials believe suspected attacker Salah Abdeslam may still be in Belgium’s capital city.

During a news conference in Malaysia, President Barack Obama took a harsher tone against ISIS.

“They’re a bunch of killers with good social media,” Obama said. “The most powerful tool we have to fight ISIL is to say that we’re not afraid.”

Obama said the world will not accept terrorist assaults on civilians as the new norm.

MORE NEWS: Gabby Petito Foundation Holds Fundraiser On Long Island

“We will cut off their financing, we will hunt down their leadership,” Obama said. “We will dismantle their networks and their supply lines and we will ultimately destroy them.”