Federal and local authorities are investigating multiple drones spotted over Morris County Monday evening.

“There is no known threat to public safety,” said a joint statement from the Morris County Prosecutor’s Office.

Authorities did not say whether they know who was flying the drones or why they flew overhead.

“The Morris County Prosecutor’s Office, Morris County Sheriff’s Office, Morris County Office of Emergency Management and Morris County Municipal Police Departments, along with our federal and state law enforcement partners, are aware of this activity and will continue to with coordinating, monitoring and investigating drone activity,” the statement said.

“This joint statement is being issued in response to rumors of drone activity spreading on social media. We encourage the public to be aware that what they read online may not be accurate.”

Picatinny Arsenal, a military base in Wharton, said the drones are not theirs and are assisting in the investigation.

“Picatinny Arsenal authorities are aware of numerous reports of unmanned aerial vehicles (UAV) over Morris County and surrounding areas on (Monday) evening,” the military base said in an emailed statement to NJ Advance Media. “We are working with several of our local, state and federal partner organizations to obtain more information about the reported activity. We remind everyone that it is unlawful to fly UAVs over Picatinny Arsenal and other federal military installations without prior authorization.”

State police and the Federal Aviation Administration had not responded to NJ Advance Media’s morning request for information as of Tuesday afternoon.