The FBI says that they do not know why drones are flying at various locations over New Jersey, but leaders say they do not believe there is any danger.

A top FBI leader was questioned on Capitol Hill about the incidents.

"Is the public at risk? Is public safety at risk? Are we concerned that there are nefarious intentions that could cause either national security or public safety incident that would put Americans at risk?” asked Republican Rep. August Pfluger.

"There is nothing that is known that would lead me to say that, but we just don't know. And that's the concerning part,” responded Robert W. Wheeler, Jr., of the FBI.

Drones have been spotted flying around New Jersey for several weeks. The sightings started in Morris County and then moved elsewhere throughout the state.

Officials at Picatinny Arsenal confirmed 11 reports of evening drone activity near the facility between Nov. 13 and Dec. 6. There were also seven unconfirmed reports – two by aircraft.

"While the source and cause of these aircraft operating in our area remain unknown, we can confirm that they are not the result of any Picatinny Arsenal-related activities,” officials wrote.

Gov. Phil Murphy will be holding a briefing Wednesday afternoon with state police and the New Jersey Office of Homeland Security.

Drones are legal in New Jersey for recreational and commercial use, but they are subject to local and Federal Aviation Administration regulations and flight restrictions. Drone operators also must be FAA certified. Most, but not all, of the drones spotted in New Jersey were larger than those typically used by hobbyists.

The FBI asks that residents share any videos or photos they may have of the flights, along with any other relevant information by calling 1-800-CALL-FBI (1-800-225-5324) or submitting a tip online.