According to local authorities, dozens of drones have been reported over New Jersey since November 18.
The drones were initially spotted near the Raritan River, which flows into the Round Valley Reservoir – the largest in New Jersey, according to the Associated Press.
The sighting soon spread to other parts of the state, including the New Jersey coast.
Some of the flights were seen near the Picatinny Arsenal — a sensitive military research facility — and near President-elect Donald Trump’s golf course in Bedminster, New Jersey.
Several drones reportedly flew over the Bronx in nearby New York on December 12, a police official told CBS News, the BBC’s US affiliate.
Officers responding to the incident saw drones flying overhead, but they soon disappeared.
Drones have also been spotted in other parts of the state, according to New York State Police.
Connecticut State Police also confirmed that “suspicious drone activity” has occurred in various parts of the state. A drone detection system has been deployed around the cities of Groton and New London.
In Maryland, former Republican Gov. Larry Hogan claimed to have seen what appeared to be “dozens” of drones over his residence in Davidsonville, about 25 miles (40 km) from Washington, DC.
“Like many who have watched these drones, I don’t know if this increased activity over our skies is a threat to public or national security,” he wrote on X. “But the public is increasingly concerned and frustrated by the complete lack of transparency and the dismissive attitude of the federal government.”
In late November, the US Air Force also confirmed that unidentified drones had been spotted over three US air bases in the UK: RAF Lakenheath and RAF Mildenhall in Suffolk and RAF Feltwell in Norfolk.
British defense sources told the BBC that suspicion had fallen on the “statesman” responsible for the incursions.
In October, the Wall Street Journal also reported that mysterious drones were seen for 17 days near US military facilities in Virginia.