WASHINGTON – Authorities charged with keeping revelers safe at some of the most prominent Independence Day celebrations revealed that, while there are no credible threats this year, security remains a major concern and people should expect a heavy law enforcement presence along with security checkpoints.

In particular, the National Park Service (NPS), which hosts arguably the most famous annual Fourth of July celebration and fireworks display in the country at the National Mall in Washington, D.C., has implemented “robust” measures to deal with the “potential risk” of vehicle attacks, reports WTOP.

“Vehicle attacks are an increasing potential risk for large events with a lot of people,” noted Mike Litterst of NPS, adding, “We are aware of that threat, and we have a robust plan in place to address those threats.”

Echoing authorities in other Fourth of July hotspots, he said that there were no credible threats, but authorities have implemented contingency measures as they continue to monitor the situation.

“While authorities insist there have been no specific threats, security has become a pressing concern in U.S. cities this holiday weekend after recent terror attacks overseas on so-called ‘soft targets’ — events and facilities where large numbers of people gather,” reports USA Today.

People should also be mindful that the “pop” sound of fireworks tends to ignite post-traumatic stress disorder (PTSD) symptoms among some veterans and other people who have endured war, reminds U.S. Army veteran Julius Strickland.

“You will never forget the sound of it coming. Ever. It never goes away so anything that reminds you of that will put you on edge,” he said, according to a local ABC News outlet in South Carolina.

On the eve of Independence Day, Monday night, Fences will be erected around the National Mall.

The thousands of people from D.C., the United States, and the world seeking to enter the famous July 4 destination will be required to pass through security checkpoints.

“Our visitors play a key role in helping us with the security and safety of the event,” said Litterst, emphasizing the federal government campaign, “if you see something, say something.”

Elsewhere in the country, law enforcement will use various tools and strategies at their disposal to keep people safe, ranging from a massive police presence to drones used to view the activities on the ground.

USA Today notes:

In Boston, police will be deploying a tethered drone for the first time to catch aerial views of the crowd and activities during the Boston Pops Fireworks Spectacular, which could attract 500,000 people along the Charles River… Meanwhile, New York City police will mount nearly 120 sand-filled trucks and “blocker vehicles” near popular viewing spots in Manhattan during the Macy’s Fireworks Show and other July Fourth events.

Besides hundreds of law enforcement officials monitoring the events, other security measures include patrols by plainclothes police officers, trained dogs, bomb detection teams, and radiation detectors for bag searches.

City planners ask people attending the events not to bring alcohol, glass containers, personal fireworks, or pets.

Moreover, most of the celebration areas across the country have been deemed “no-drone” events, which means personal unmanned aircraft are prohibited.