As the preparations get underway at the Boston Esplanade for the Fourth of July, there's a new terror concern.
NBC News has learned from multiple intelligence and law enforcement sources that there is a heightened state of concern about an ISIS-inspired attack within the U.S. extending through the July 4 weekend.
Over the past few years, especially since the Boston Marathon bombings, security at the Esplanade on the fourth has been extremely tight.
In-depth news coverage of the Greater Boston Area.
Signs along the Charles River tell people "If you see something, say something."
"The world is getting a little more serious," Bowton University Student Jake Dibattista said. "Organizations like ISIS kind of taking the fight to home soil."
A new bulletin from the U.S. Dept of Homeland Security and the FBI says they continue to stay in contact with state and local police about what they know.
"We are encouraging all law enforcement to be vigilant and prepared. We will also adjust security measures, seen and unseen, as necessary to protect the American people," said Department of Homeland Security Secretary Jeh Johnson in a statement.
At the Esplanade this year, State Police Col. Tim Alben says there are several new cameras to help them monitor the event.
In addition, there will be nine medical stations standing by for any emergencies, Jim Wholley of Boston EMS said.
At Fenway Park, the concerns are not being taken lightly.
"The Red Sox are aware of the circumstances and are working closely with local, state, and federal partners," the team said in a statement.