A series of unexplained drone sightings in New Jersey and surrounding areas sparked calls for a limited state of emergency to be declared over the region, with some officials demanding a ban on all drones until the mystery is solved.

“The State of New Jersey should issue a limited state of emergency banning all drones until the public receives an explanation regarding these multiple sightings,” state Sen. Jon Bramnick said in a statement Tuesday.

The sightings, which began in mid-November, have been reported in at least 10 counties across New Jersey, with some drones spotted near critical infrastructure, including reservoirs, electric transmission lines, rail stations, police departments, and military installations.

According to the Federal Aviation Administration (FAA), the first reported sighting occurred on November 18 near Morris County, New Jersey. Since then, numerous sightings have been reported, with some drones described as traveling in clusters and spanning up to 6 feet in diameter.

The New Jersey State Police and the FBI are leading the investigation, with assistance from other federal agencies. The FBI has asked the public to report any information related to the drones, including in several areas along the Raritan River.

Despite assurances from Governor Phil Murphy that there is no known threat to the public, concerns have been raised by residents and officials across the state. U.S. Senator Cory Booker has pushed for more information from federal investigators, citing a growing sense of uncertainty and urgency across the state.

The Pentagon has denied speculation that the drones may originate from a foreign entity or adversary, with Deputy Pentagon Press Secretary Sabrina Singh saying that “there is no Iranian ship off the coast of the United States, and there’s no so-called mothership launching drones towards the United States.”