Multiple drones are seen over Bernardsville, N.J. on Dec. 5. Brian Glenn/TMX via AP

Three days ago, Gov. Phil Murphy attempted to soothe worries that the mysterious drones flying in New Jersey airspace posed a threat to public safety. But growing concern – and additional sightings – moved Murphy to write to President Biden on Thursday, emphasizing the need for more federal resources.

Murphy wrote that “existing laws limit the ability of state and local law enforcement to counter” the drones, also referred to as unmanned aircraft systems. Murphy stressed that the drones have “raised more questions than answers” and has led to the circulation of conspiracy theories across the internet as people search for explanations.

Action to address the drones, Murphy added, rests “squarely on the shoulders of the federal government.”

The New Jersey State Police have received reports of drones since Nov. 18, Murphy wrote. The sightings have been spotted near homes, businesses, military research facilities and President-elect Donald Trump’s golf course in Bedminster.

Federal investigators said they don’t have answers yet but added they don’t believe the drones pose a public threat. The FBI’s Newark Field Office and the New Jersey State Police have been investigating the reports for about a month, and the Federal Aviation Administration has imposed drone flight restrictions near Bedminster and Picatinny while authorities investigate.

Earlier this week, the Bowie Police Department in Prince George’s County began receiving calls from community members about drone sightings and the calls have continued.

While the department remains unsure where the drones are coming from, they can confirm they are not city of Bowie drones and are looking into the sightings, a spokesperson for the department said.

Former Maryland governor Larry Hogan also wrote on X that he observed drone activity for 45 minutes on Thursday night from his home 25 miles outside of Washington.

Flying a drone for recreational or non-recreational use between 15 and 30 miles from D.C. is allowed under specific operating conditions, according to the FAA. However, drone use is prohibited within a less-than-15-mile radius “inner ring” of the Washington area, centered at Ronald Reagan Washington National Airport.

Bowie lies outside of these permanent FAA restrictions, and there is no FAA flight restriction in place at that location as of Friday afternoon. Drones are legal for both recreational and commercial use, as long as operators follow local and FAA regulations and hold FAA certification. Many reports show the drones are larger than those generally used for recreation.

Sal Rizzo contributed to this report.